Eye care questions and answers
WHY DO I NEED AN EYE EXAM?
Regardless of your age or physical health, it’s important to have regular eye exams.During a complete eye exam, your eye doctor will not only determine your prescription for eyeglasses or contact lenses, but will also check your eyes for common eye diseases, assess how your eyes work together as a team and evaluate your eyes as an indicator of your overall health.
Who should get their eyes examined?
Eye examinations are an important part of health maintenance for everyone. Adults should have their eyes tested to keep their prescriptions current and to check for early signs of eye disease. For children, eye exams can play an important role in normal development.
Vision is closely linked to the learning process. Children who have trouble seeing or interpreting what they see will often have trouble with their schoolwork. Many times, children will not complain of vision problems simply because they don't know what "normal" vision looks like. If your child performs poorly at school or exhibits a reading or learning problem, be sure to schedule an eye examination to rule out an underlying visual cause.
What is the eye doctor checking for?
In addition to evaluating whether you have nearsightedness, farsightedness or astigmatism, your eye doctor will check your eyes for eye diseases and other problems that could lead to vision loss. Here are some examples of the conditions that your eye doctor will be looking for:
- Amblyopia: This occurs when the eyes are misaligned or when one eye has a much different prescription than the other. The brain will "shut off" the image from the turned or blurry eye. If left untreated, amblyopia can stunt the visual development of the affected eye, resulting in permanent vision impairment. Amblyopia is often treated by patching the stronger eye for periods of time.
- Strabismus: Strabismus is defined as crossed or turned eyes. Your eye doctor will check your eyes' alignment to be sure that they are working together. Strabismus causes problems with depth perception and can lead to amblyopia.
- Eye Diseases: Many eye diseases, such as glaucoma and diabetic eye disease, have no obvious symptoms in their early stages. Your eye doctor will check the health of your eyes inside and out for signs of early problems. In most cases, early detection and treatment of eye diseases can help reduce your risk for permanent vision loss.
- Other Diseases: Your eye doctor can detect early signs of some systemic conditions and diseases by looking at your eye's blood vessels, retina and so forth. They may be able to tell you if you are developing high blood pressure, high cholesterol or other problems.
For example, diabetes can cause small blood vessel leaks or bleeding in the eye, as well as swelling of the macula (the most sensitive part of the retina), which can lead to vision loss. It’s estimated that one-third of Americans who have diabetes don't know it; your eye doctor may detect the disease before your primary care physician does, especially if you're overdue for a physical.
What’s the difference between a vision screening and a complete eye exam?
Vision screenings are general eye tests that are meant to help identify people who are at risk for vision problems. Screenings include brief vision tests performed by a school nurse, pediatrician or volunteers. The eye test you take when you get your driver's license renewed is another example of a vision screening.
A vision screening can indicate that you need to get an eye exam, but it does not serve as a substitute for a comprehensive eye exam.
A comprehensive eye examination is performed by an eye doctor and will involve careful testing of all aspects of your vision. Based upon the results of your exam, your doctor will then recommend a treatment plan for your individual needs. Remember, only an eye doctor can provide a comprehensive eye exam. Most family physicians and pediatricians are not fully trained to do this, and studies have shown that they can miss important vision problems that require treatment.
Treatment plans can include eyeglasses or contact lenses, eye exercises or surgery for muscle problems, medical treatment for eye disease or simply a recommendation that you have your eyes examined again in a specified period of time.
No matter who you are, regular eye exams are important for seeing more clearly, learning more easily and preserving your vision for life.
WHAT HAPPENS AT THE EYE EXAM?
A comprehensive eye exam includes a number of tests and procedures to examine and evaluate the health of your eyes and the quality of your vision. These tests range from simple ones, like having you read an eye chart, to complex tests, such as using a high-powered lens to examine the health of the tissues inside of your eyes.
Here are some tests you are likely to encounter during a routine comprehensive eye exam:
This test helps your doctor get a good approximation of your eyeglasses prescription. For retinoscopy, the room lights are dimmed and an instrument containing wheels of lenses (called a phoropter) is positioned in front of your eyes. You will be asked to look at an object across the room (usually the big “E” on the wall chart or screen) while your doctor shines a light from a hand-held instrument into your eyes from arm’s length and flips different lenses in front of your eyes.
Based on the way the light reflects from your eye during this procedure, your doctor can get a very good idea of what your eyeglasses prescription should be. This test is especially useful for children and non-verbal patients who are unable to accurately answer the doctor's questions.
With the widespread use of automated instruments to help determine eyeglass prescriptions today, many doctors forgo performing retinoscopy during comprehensive eye exams.
However, this test can provide valuable information about the clarity of the internal lens and other media inside the eye. So doctors who no longer perform this test routinely may still use it when examining someone who may be at risk of cataracts or other internal eye problems.
This is the test your doctor uses to determine your exact eyeglasses prescription. During refraction, the doctor puts the phoropter in front of your eyes and shows you a series of lens choices. He or she will then ask you which of the two lenses in each choice (“1 or 2,” “A or B,” for example) make the letters on the wall chart look clearer.
Based on your answers, your doctor will determine the amount of nearsightedness, farsightedness and/or astigmatism you have, and the eyeglass lenses required to correct these vision problems (which are called refractive errors).
Autorefractors and aberrometers
Your eye doctor also may use an autorefractor or aberrometer to help determine your glasses prescription. With both devices, a chin rest stabilizes your head while you typically look at a pinpoint of light or other image.
An autorefractor evaluates the way an image is focused on the retina, where vision processing takes place, without the need for you to say anything. This makes autorefractors especially useful when examining young children or people who may have difficulty with a regular (“subjective”) refraction. Automated refractions and subjective refractions are often used together during a comprehensive exam to determine your eyeglasses prescription.
An aberrometer uses advanced wavefront technology to detect even obscure vision errors based on the way light travels through your eye.
While there are many ways for your eye doctor to check how your eyes work together, the cover test is the simplest and most common.
During a cover test, the eye doctor will have you focus on a small object at distance and will then cover each of your eyes alternately while you stare at the target. As they do this, eye doctors observe how much each eye has to move when uncovered to pick up the fixation target. The test is then repeated as you focus on a near object.
Cover tests can detect even very subtle misalignments that can interfere with your eyes working together properly (binocular vision) and cause amblyopia or “lazy eye.”
The slit lamp is an instrument that the eye doctor uses to examine the health of your eyes. Also called a biomicroscope, the slit lamp gives your doctor a highly magnified view of the structures of the eye, including the lens behind the pupil, in order to thoroughly evaluate them for signs of infection or disease.
The slit lamp is basically an illuminated binocular microscope that’s mounted on a table and includes a chin rest and head band to position the patient’s head properly. With the help of hand-held lenses, your doctor can also use the slit lamp to examine the retina (the light-sensitive inner lining of the back of the eye.)
Tonometry (glaucoma testing)
Tonometry is the name for a variety of tests that can be performed to determine the pressure inside the eye. Elevated internal eye pressure can cause glaucoma, which is vision loss due to damage to the sensitive optic nerve in the back of the eye.
The most common method used for tonometry is the “air puff” test – where an automated instrument discharges a small burst of air to the surface of your eye. Based on your eye's resistance to the puff of air, the machine calculates the pressure inside your eye – called your intraocular pressure (IOP).
Though the test itself can be startling, nothing but air touches your eye during this measurement and there’s no risk of eye injury from the air puff test.
Another popular way to measure eye pressure is with an instrument called an applanation tonometer, which is usually attached to a slit lamp. For this test, a yellow eye drop is placed on your eyes. Your eyes will feel slightly heavy when the drops start working. This is not a dilating drop — it is simply a numbing agent combined with a yellow dye. Then the doctor will have you stare straight ahead in the slit lamp while he or she gently rests the bright-blue glowing probe of the tonometer on the front of each eye and manually measures the intraocular pressure. Like the air puff test, applanation tonometry is painless and takes just a few seconds.
Since glaucoma is often the result of an increase of pressure inside the eye, these are important tests for ensuring the long-term health of your eyes.
Your comprehensive exam may include the use of dilating drops. These medicated eye drops enlarge your pupil so your doctor can get a better view of the internal structures in the back of the eye. Dilating drops usually take about 20 minutes to start working. When your pupils are dilated, you will be sensitive to light because more light is getting into your eye. You may also notice difficulty reading or focusing on close objects. These effects can last for up to several hours, depending on the strength of the drops used.
If you don’t have sunglasses to wear after the exam, disposable sunglasses will be provided to help you drive home. Dilation is very important for people with risk factors for eye disease, because it allows for a more thorough evaluation of the health of the inside of your eyes.
These are the most common tests performed during a standard comprehensive eye exam. Depending on your particular needs, your doctor may perform additional tests or schedule them to be performed at a later date.
WHAT IS VISION THERAPY?
Many individuals, especially children, have vision problems other than simple refractive errors such as nearsightedness, farsightedness and astigmatism. These “other” vision problems include amblyopia (“lazy eye”), eye alignment or eye teaming problems, focusing problems, and visual perceptual disorders. Left untreated, these non-refractive vision problems can cause eyestrain, fatigue, headaches, and learning problems.
What is vision therapy?
Vision therapy (also called orthoptics or vision training) is an individualized program of eye exercises and other methods to treat non-refractive vision problems. The therapy is usually performed in an optometrist’s office, but most treatment plans also include daily visual tasks and eye exercises to be performed at home.
Optometrists who specialize in vision therapy and the treatment of learning-related vision problems are sometimes called behavioral optometrists or developmental optometrists.
Can vision therapy eliminate the need for glasses?
Vision therapy is NOT the same as self-help programs that claim to reduce refractive errors and the need for glasses. There is no scientific evidence that these “throw away your glasses” programs work, and most eye care specialists agree they are a hoax.
In contrast, vision therapy is approved by the American Optometric Association (AOA) for the treatment of non-refractive vision problems, and there are many studies that demonstrate its effectiveness.
The degree of success achieved with vision therapy, however, depends on a number of factors, including the type and severity of the vision problem, the patient’s age and motivation, and whether the patient performs all eye exercises and visual tasks as directed. Not every vision problem can be resolved with vision therapy.
Vision therapy is customized and specific
The activities and eye exercises prescribed as part of a vision therapy program are tailored to the specific vision problem (or problems) a child has. For example, if a child has amblyopia, the therapy usually includes patching the strong eye, coupled with visual tasks or other stimulation techniques to develop better visual acuity in the weak eye. Once visual acuity is improved in the amblyopic eye, the treatment plan may then include eye teaming exercises to foster the development of clear, comfortable binocular vision to improve depth perception and reading comfort.
Vision therapy and learning disabilities
Vision therapy does not correct learning disabilities. However, children with learning disabilities often have vision problems as well. Vision therapy can correct underlying vision problems that may be contributing to a child’s learning problems.
Be sure to tell us if your child has been diagnosed as having a learning disability. If we find vision problems that may be contributing to learning problems, we can communicate with their teachers and other specialists to explain our findings. Often, vision therapy can be a helpful component of a multidisciplinary approach to remediating learning problems.
Schedule a comprehensive eye exam
If you suspect your child has a vision problem that may be affecting their performance in school, the first step is to schedule a comprehensive eye exam so we can determine if such a problem exists. If learning-related vision problems are discovered, we can then discuss with you whether a program of vision therapy would be helpful.
If we don’t provide the type of vision therapy your child needs, we will refer you to an optometrist who specializes in developmental vision and vision therapy.
LENS OPTIONS FOR EYEGLASSES
When it comes to choosing eyeglass lenses, it’s no longer a simple choice of “glass or plastic?” Let’s look at your many options in eyeglass lenses in detail:
Want thinner, lighter lenses? Choose a high index lens material.
Nearly everyone can benefit from thinner, lighter lenses. High index lenses can be up to 50% thinner than regular glass or plastic lenses, and they’re usually much lighter, too.
Though these lenses are especially beneficial if you have a strong eyeglasses prescription, they can make a noticeable difference in the appearance of virtually any pair of glasses. High index lenses bend light more efficiently than regular glass or plastic lenses, so less lens material is required to correct your vision.
Various high index lenses are available today in different price points based on how much thinner they are compared to regular plastic lenses. The lenses are classified by their “index of refraction” (or “refractive index”).
Generally, lenses with a higher index of refraction will be thinner (and usually more expensive) than lenses with a lower index. The index of refraction of regular plastic lenses is 1.50. The refractive index of high index plastic lenses ranges from 1.53 to 1.74. Those in the range of 1.53 to 1.59 are about 20% thinner than regular plastic lenses, whereas 1.74 high index lenses are about half the thickness of regular plastic lenses.
Most popular lens designs (single vision, bifocal, progressive, photochromic, etc.) come in high-index materials, and your doctor or optician will know which ones are available in your prescription. Bifocal and trifocal high index lenses are also available, though the selection is more limited.
Note: High index lenses reflect more light than regular glass or plastic lenses, so anti-reflective (AR) coating is highly recommended for these lenses (see below).
Slim down with aspheric lenses
To make high index lenses even more attractive, most of them have an “aspheric” design. This means that instead of having a round (or “spherical”) curve on the front surface, these lenses have a curve that gradually changes from the center to the lens to the periphery. This makes aspheric lenses noticeably flatter for a slimmer, more attractive lens profile.
Though aspheric lenses offer advantages for all prescriptions, they are particularly beneficial if you are farsighted. Aspheric lenses greatly reduce the magnified “bug-eye” look caused by regular, highly curved lenses for farsightedness, and they greatly reduce the “bulge” of the lenses from the frame. And because they have a slim profile, aspheric lenses have less lens mass, making them much lighter. Aspheric lenses also provide superior peripheral vision compared to conventional lenses.
Note: Because they have flatter curves than regular lenses, aspheric lenses may cause more noticeable reflections. Anti-reflective (AR) coating is recommended for these lenses (see below).
Polycarbonate and Trivex lenses: Tough as nails.
Polycarbonate and Trivex lenses are special high index lenses that offer superior impact resistance. These lenses are up to 10 times more impact resistant than regular plastic lenses, making them an ideal choice for children’s eyewear, safety glasses, and for anyone with an active lifestyle who wants a thinner, lighter, safer lens.
Polycarbonate lenses have a refractive index of 1.59, making them 20% to 25% thinner than regular plastic lenses. They are also up to 30% lighter than regular plastic lenses, making them a good choice for anyone who is sensitive to the weight of eyeglasses on their nose.
Trivex lenses may be slightly thicker than polycarbonate lenses, but they provide comparable impact resistance and, like polycarbonate lenses, they block 100% of the sun’s harmful UV rays.
AR coating: Better vision, better appearance.
All eyeglass lenses reflect some light, reducing the amount of light that enters the eye to form visual images. This can have an impact on vision, especially under low-light conditions, like when driving at night. Lens reflections can also cause glare, further reducing vision in these situations.
The amount of light reflected depends on the lens material. Conventional glass or plastic lenses reflect about 8% of incident light, so only 92% of available light enters the eye for vision. Thinner, lighter lenses made of high index materials reflect up to 50% more light than regular glass or plastic lenses (up to 12% of available light).
Anti-reflective (AR) coating reduces lens reflections and allows more light to enter the eye for better night vision. Regardless of the lens material, eyeglass lenses with AR coating transmit over 99% of available light to the eye.
By eliminating surface reflections, anti-reflective coating also makes your lenses nearly invisible. This greatly improves the appearance of your eyewear and allows others to see your eyes, not the reflections in your glasses.
When cleaning lenses with anti-reflective coating, be sure to use the products recommended by your optician. Because AR coating eliminates reflections that can hide small scratches, you’ll want to take care not to scratch AR-coated lenses, as scratches on these lenses may be more visible than scratches on an uncoated lens.
No eyeglass lens material – not even glass – is scratch-proof. However, a lens that is treated front and back with a clear, hard coating does become more resistant to scratching, whether it's from dropping your glasses on the floor or occasionally cleaning them with a paper towel. Kids' lenses, especially, benefit from a scratch-resistant hard coat.
To safeguard your investment in your eyewear, scratch-resistant coating should be considered for all eyeglass lenses. The only exception is glass lenses, which are naturally hard and scratch-resistant.
To further protect your eyeglasses from scratches, keep your glasses in a protective case when you’re not wearing them. Also, never clean your lenses without first rinsing them with a cleaning solution or water. Rubbing a dry, dusty or dirty lens with a cleaning cloth or towel can cause scratches, even on lenses with a scratch-resistant coating.
Ultraviolet (UV) treatment
Just as you use sunscreen to keep the sun's UV rays from harming your skin, UV treatment in eyeglass lenses blocks those same rays from damaging your eyes. Overexposure to ultraviolet light is thought to be a cause of cataracts, retinal damage and other eye problems.
Most high index lenses have 100% UV protection built-in. But with regular plastic lenses, a lens treatment is required for these lenses to block all UV rays. This UV treatment does not change the appearance of the lenses and is quite inexpensive.
Photochromic lenses: Right in any light
Photochromic lenses are convenient indoor-outdoor eyeglass lenses that automatically darken to a sunglass shade outside when exposed to sunlight, and then quickly return to a clear state indoors. These lenses also provide 100% protection from the sun’s UV rays, and are available in a wide variety of lens materials and designs, including bifocal and progressive lenses.
The amount of darkening that most photochromic lenses undergo depends on how much UV radiation to which they are exposed. As a general rule, these lenses won't get as dark behind the windshield of your car or truck because the glass blocks out much of the sun’s UV rays that cause the lenses to change color.
We’re here to help!
With so many new lens products available, it’s hard to know all your options and decide which lenses are best for you. Rely on our expertise to make selecting your eyeglasses easy and fun. Our trained staff welcomes the opportunity to help you find the perfect eyewear for your personal style and vision requirements.
WHAT ARE COMPUTER GLASSES?
When you work at a computer for any length of time, it's common to experience blurred vision and other symptoms of computer vision syndrome (CVS). Viewing computer-generated print and images on a screen or monitor for prolonged periods is harder on the eyes than viewing a similar amount of material on the printed pages of a book or magazine.
If you're under age 40, blurred vision during computer use may be due to your eyes being unable to remain accurately focused on your screen for sustained periods. Or you may have a hard time quickly and accurately changing focus, such as when you shift your gaze from your monitor to your keyboard and back again. This problem, called lag of accommodation, can cause eyestrain and headaches — two common symptoms of CVS.
If you're over age 40, the onset of presbyopia — the normal age-related loss of near focusing ability — can make focusing on a computer screen even more difficult, further increasing the risk of eyestrain, headaches and eye fatigue.
So what can you do to make your eyes more comfortable and function more efficiently during computer use? Have your eye doctor prescribe specially-designed computer glasses.
Customized computer glasses can make a world of difference. These special-purpose glasses are prescribed specifically to reduce eyestrain and give you the most comfortable vision at your computer.
I already wear glasses. Do I really need computer glasses?
If you already wear prescription eyeglasses or reading glasses, you may be tempted to dismiss the idea of computer glasses. But eyeglasses prescribed for general purpose wearing are often not well-suited for prolonged computer work.
Why? When working at a computer, your eyes are generally 20 to 26 inches from your computer screen. This distance is considered the intermediate zone of vision — closer than driving (distance) vision, but farther away than reading (near) vision.
Most young people wear eyeglasses to correct their distance vision. Reading glasses are prescribed to correct near vision only. And bifocals prescribed for those over age 40 with presbyopia correct only near and far. None of these eyeglasses are optimized for the intermediate zone of vision used during computer work.
Even trifocals and progressive lenses, which do include the correct power for intermediate vision, have only a small portion of the lens dedicated to this area — not nearly a large enough area for comfortable prolonged computer work.
Without the appropriate eyewear, computer users can often end up with blurred vision, eyestrain, and headaches — the hallmark symptoms of computer vision syndrome (CVS). Worse still, many people try to compensate for their blurred vision by leaning forward, or by tipping their head to look through the bottom portion of their glasses. These unnatural postures can lead to headaches, neck and shoulder pain, and backaches.
Computer glasses reduce errors and increase productivity
Are computer glasses worth the extra cost of a second pair of glasses?
Yes, they are. Research has shown that, in addition to increasing comfort and decreasing the risk of CVS, prescription computer glasses can reduce errors and losses of productivity caused by vision problems during computer work.
A study conducted at the University of Alabama - School of Optometry found that even minor changes from the optimum lens power for computer work can cause a 38% decrease in accuracy for tasks performed on a computer and a 9% loss in worker productivity.
The researchers concluded that, because of productivity gains from workers wearing computer glasses, companies that pay for computer eyewear for their employees could experience a benefit/cost ratio of $18 for every $1 spent.
Computer lens designs
There are a number of special purpose lens designs that work well for computer glasses. Because these lenses are prescribed specifically for computer use, they are unsuitable for driving or general purpose wear.
The simplest computer glasses have single vision lenses with a modified lens power prescribed to give the most comfortable vision at the user's computer screen. These lenses relax the amount of focusing the eyes have to do to keep images on the computer screen clear and provide the largest field of view, reducing the need for head tilting and other unnatural posture changes during computer work.
For older computer users, a specially designed progressive lens for computer use is sometimes a better option. Progressive lenses for computer use have a larger intermediate zone than regular progressive lenses for a wider, more comfortable view of the computer screen.
Another option for presbyopic computer users is a lined trifocal, with a larger intermediate zone than regular trifocals. Still another possibility is an occupational bifocal, with the top part of the lens for intermediate vision (computer screen) and the bottom portion for near vision (reading).
Your eyecare professional can help you decide which lens design will best suit your needs.
Lens coatings and treatments
Anti-reflective (AR) coating can make your computer glasses even more comfortable. This coating reduces glare caused by reflections of overhead fluorescent lighting that can occur in uncoated eyeglass lenses.
Also, because many office environments are too bright for optimum visual comfort, a light tint is often a good idea as well. Special tints are available that selectively block different wavelengths of indoor lighting for greater comfort.
WHAT IS A CONTACT LENS FITTING AND WHY DO I NEED ONE?
For many people, contact lenses provide greater convenience and more satisfying vision correction than eyeglasses. Here’s what’s involved in a typical contact lens exam and fitting:
A comprehensive eye exam comes first
Before being fit with contact lenses, a comprehensive eye exam is performed. This exam, your eye doctor determines your prescription for corrective lenses (just a glasses prescription at this point) and checks for any eye health problems or other issues that may interfere with successful contact lens wear.
If all looks good during your eye exam, the next step is a contact lens consultation and fitting.
What to expect during a contact lens fitting
The first step in a contact lens fitting is a consideration of your lifestyle and your preferences regarding contact lenses, such as whether you might want to change your eye color with color contact lenses or if you're interested in options such as daily disposables or overnight wear. Although most people choose soft contact lenses, the advantages and disadvantages of rigid gas permeable (RGP) lenses will likely be discussed as well.
If you are over age 40 and need bifocals, your eye doctor or contact lens specialist will discuss ways to deal with this need, including multifocal contact lenses and monovision (a prescribing technique where one contact lens corrects your distance vision and the other lens corrects your near vision).
Contact lens measurements
Just as one shoe size doesn't fit all feet, one contact lens size doesn't fit all eyes. If the curvature of a contact lens is too flat or too steep for your eye's shape, you may experience discomfort or even damage to your eye. Measurements that will be taken to determine the best contact lens size and design for your eyes include:
Corneal curvature: An instrument called a keratometer is used to measure the curvature of your eye's clear front surface (cornea). This measurement helps your doctor select the best curve and diameter for your contact lenses.
If your eye's surface is found to be somewhat irregular because of astigmatism, you may require a special lens design of lens known as a “toric” contact lens. At one time, only gas permeable contact lenses could correct for astigmatism. But there are now many brands of soft toric lenses, which are available in disposable, multifocal, extended wear and colored versions.
In some cases, a detailed mapping of the surface of your cornea (called corneal topography) may be done. Corneal topography provides extremely precise details about surface characteristics of the cornea and creates a surface "map" of your eye, with different contours represented by varying colors.
- Pupil and iris size: The size of your pupil and iris (the colored part of your eye) can play an important role in determining the best contact lens design, especially if you are interested in RGP contact lenses. These measurements may be taken with a lighted instrument called a biomicroscope (also called a slit lamp) or simply with a hand-held ruler or template card.
- Tear film evaluation: To be successful wearing contact lenses, you must have an adequate tear film to keep the lenses and your cornea sufficiently moist and hydrated. This test may be performed with a liquid dye placed on your eye so your tears can be seen with a slit lamp or with a small paper strip placed under your lower lid to see how well your tears moisten the paper. If you have dry eyes, contact lenses may not be right for you. Also, the amount of tears you produce may determine which contact lens material will work best for you.
In many cases, trial lenses will be used to verify the contact lens selection. Lenses will be placed on your eye and your doctor will use the slit lamp to evaluate the position and movement of the lenses as you blink and look in different directions. You will also be asked how the lenses feel.
You'll typically need to wear these trial lenses at least 15 minutes so that any initial excess tearing of the eye stops and your tear film stabilizes. If all looks good, you will be given instructions on how to care for your lenses and how long to wear them. You will also receive training on how to handle, apply and remove the lenses.
Follow-up visits confirm the fit and safety
Your contact lens fitting will involve a number of follow-up visits so your doctor can confirm the lenses are fitting your eyes properly and that your eyes are able to tolerate contact lens wear. A dye (like the one used to evaluate your tear film) may be used to see if the lenses are causing damage to your cornea or making your eyes become too dry.
Often, your doctor will be able to see warning signs before you are aware a problem with your contact lens wear is developing. If such warning signs are evident in your follow-up visits, a number of things may be recommended, including trying a different lens or lens material, using a different lens care method, or adjusting your contact lens wearing time. In occasional cases, it may be necessary to discontinue contact lens wear altogether.
Your contact lens prescription
After finding a contact lens that fits properly, is comfortable for you, and provides good vision, your doctor will then be able to write a contact lens prescription for you. This prescription will designate the contact lens power, the curvature of the lens (called the base curve), the lens diameter, and the lens name and manufacturer. In the case of RGP contact lenses, additional specifications may also be included.
Routine contact lens exams
Regardless of how often or how long you wear your contact lenses, your eyes should be examined at least once a year to make sure your eyes are continuing to tolerate contact lens wear and show no signs of ill effects from the lenses.
WHAT ARE PROGRESSIVE LENSES AND HOW DO THEY WORK?
Progressive addition lenses (also called progressives or PALs) are the most popular multifocal lenses sold in the United States. Sometimes called "no-line bifocals," these line-free multifocals provide a more complete vision solution than bifocals. Instead of having just two lens powers like a bifocal – one for distance vision and one for up close – progressives have a gradual change in power from the top to the bottom of the lens, providing a range of powers for clear vision far away, up close and everywhere in between.
Progressive lenses provide the closest thing to natural vision after the onset of presbyopia – the normal age-related loss of near vision that occurs typically after age 40. The gradual change of power in progressives allows you to look up to see in the distance, look straight ahead to clearly see your computer or other objects at arm’s length, and drop your gaze downward to read and do fine work comfortably close up.
While progressive lenses typically are worn by middle-aged and older adults, a recent study suggests that they may also be able to slow progression of myopia in children whose parents also are nearsighted.
Choosing the right frame for progressive lenses
Because a progressive lens changes in power from top to bottom, these lenses require frames that have a vertical dimension that is tall enough for all powers to be included in the finished eyewear. If the frame is too small, the distance or near zone of the progressive lens may end up too small for comfortable viewing when the lens is cut to fit into the frame.
To solve this problem and to expand options in frame styles, most progressive lens manufacturers now offer “short corridor” lens designs that fit in smaller frames. Today, an experienced optician can usually find a progressive lens that will work well in nearly any frame you choose.
Different progressives for different purposes
Many different progressive lenses are available on the market today, and each has its own unique design characteristics. There are even progressive lenses designed for specific activities. For example, for the computer user, special “occupational” progressive lenses are available with an extra-wide intermediate zone to maximize comfort when working at the computer for prolonged periods of time. Other designs for office work have a larger reading portion.
It may take a few minutes to a few days before you are completely comfortable with your first pair of progressive lenses, or when you change from one progressive lens design to another. You have to learn how to use the lenses, so you are always looking through the best part of the lens for the distance you are viewing. You also may notice a slight sensation of movement when you quickly move your eyes or your head until you get used to the lenses. But for most wearers, progressive lenses are comfortable right from the start.
Let us help
With so many options in eyewear today, choosing the right frame and lenses can seem overwhelming. Let us help. Our professional opticians can discuss the advantages of the latest progressive lenses with you and help you find the lenses and frames that best match your needs.
HOW OFTEN DO I NEED AN EYE EXAM?
Children: Some experts estimate that approximately 5 percent to 10 percent of pre-schoolers and 25 percent of school-aged children have vision problems. According to the American Optometric Association (AOA), all children should have their eyes examined at 6 months of age, at age 3 and again at the start of school. Children without vision problems or risk factors for eye or vision problems should then continue to have their eyes examined at least every two years throughout school.
Children with existing vision problems or risk factors should have their eyes examined more frequently. Common risk factors for vision problems include:
- premature birth
- developmental delays
- turned or crossed eyes
- family history of eye disease
- history of eye injury
- other physical illness or disease
The AOA recommends that children who wear eyeglasses or contact lenses should have their eyes examined at least every 12 months or according to their eye doctor’s instructions.
Adults: The AOA also recommends an annual eye exam for any adult who wears eyeglasses or contacts. If you don't normally need vision correction, you still need an eye exam every two to three years up to the age of 40, depending on your rate of visual change and overall health. Doctors often recommend more frequent examinations for adults with diabetes, high blood pressure and other disorders, because many diseases can have an impact on vision and eye health.
If you are over 40, it's a good idea to have your eyes examined every one to two years to check for common age-related eye problems such as presbyopia, cataracts and macular degeneration. Because the risk of eye disease continues to increase with advancing age, everyone over the age of 60 should be examined annually.