Optometrists are independent, primary health care providers who examine, diagnose, treat, and manage diseases and disorders of the visual system, the eye and associated structures as well as diagnose related systemic conditions. Optometrists are an integral part of the health care team. As eye care practitioners, they are skilled in the co-management of eye health and vision care. They examine the structures of the eye to detect and diagnose:
- Vision conditions such as nearsightedness, farsightedness, astigmatism and presbyopia
- Binocular vision conditions such as convergence insufficiency, which can cause eye discomfort and difficulty reading
- Eye diseases such as glaucoma, cataracts and retinal disorders
- Systemic diseases such as hypertension and diabetes
Optometrists prescribe and/or provide eyeglasses, contact lenses, low vision aids and vision therapy. They prescribe medications to treat eye diseases and perform certain surgical procedures. Optometrists also do testing to determine the patient’s ability to focus and coordinate the eye, judge depth perception, and see colors accurately.
In other words, is it what you see at 20 feet, they see at 200 ft or vice versa?
This is a common question. 20/200 vision although significantly less than the standard 20/20, is not real bad. It is moderate. 20/200 vision is certainly reduced enough that it should be corrected with glasses or contacts. This may also depend on the patient’s visual needs, but most people would feel that this is blurry (poor) vision if uncorrected. The 20/200 visual measurement means that at 20 feet away you see a size 200 letter. The first number is the distance away that the vision is checked and the second number is the size of the letter that you can read. The larger the number the larger the letter size. If you are 20/200, it means that what you see at 20 ft. is what a person 20/20 can see at 200 ft.
When the pupil is functioning normally, shining a bright light into a person’s eyes causes the pupil to constrict. Using dilating drops allows the optometrist to use the instruments necessary to evaluate the posterior portion of the eye, including the retina and optic nerve, without the pupil becoming smaller. In fact, the large, dilated pupil allows a much better view all the way to the “far corners” of the retina.
Nearsightedness, or myopia, as it is medically termed, is a vision condition in which near objects are seen clearly, but distant objects do not come into proper focus. Nearsightedness occurs if your eyeball is too long or the cornea has too much curvature, so the light entering your eye is not focused correctly.
Nearsightedness is a very common vision condition that affects nearly 30 percent of the U.S. population. Some evidence supports the theory that nearsightedness is hereditary. There is also growing evidence that nearsightedness may be caused by the stress of too much close vision work. It normally first occurs in school age children. Since the eye continues to grow during childhood, nearsightedness generally develops before age 20.
A sign of nearsightedness is difficulty seeing distant objects like a movie or TV screen or chalkboard. A comprehensive optometric examination will include testing for nearsightedness. Your optometrist can prescribe eyeglasses or contact lenses to optically correct nearsightedness by altering the way the light images enter your eyes. You may only need to wear them for certain activities, like watching TV or a movie or driving a car, or they may need to be worn for all activities.
Refractive surgery or laser procedures are also possible treatments for nearsightedness as is orthokeratology. Orthokeratology is a non-invasive procedure that involves the wearing of a series of specially-designed rigid contact lenses to progressively reshape the curvature of the cornea over time.
Farsightedness, or hyperopia, as it is medically termed, is a vision condition in which distant objects are usually seen clearly, but close ones do not come into proper focus. Farsightedness occurs if your eyeball is too short or the cornea has too little curvature, so light entering your eye is not focused correctly.
Common signs of farsightedness include difficulty in concentrating and maintaining a clear focus on near objects, eye strain, fatigue and/or headaches after close work, aching or burning eyes, irritability or nervousness after sustained concentration.
Common vision screenings, often done in schools, are generally ineffective in detecting farsightedness. A comprehensive optometric examination will include testing for farsightedness.
In mild cases of farsightedness, your eyes may be able to compensate without corrective lenses. In other cases, your optometrist can prescribe eyeglasses or contact lenses to optically correct farsightedness by altering the way the light enters your eyes.
Presbyopia is a vision condition in which the crystalline lens of your eye loses its flexibility, which makes it difficult for you to focus on close objects.
Presbyopia may seem to occur suddenly, but the actual loss of flexibility takes place over a number of years. Presbyopia usually becomes noticeable in the early to mid-forties. Presbyopia is a natural part of the aging process of the eye. It is not a disease and it cannot be prevented.
Some signs of presbyopia include the tendency to hold reading materials at arm’s length, blurred vision at normal reading distance and eye fatigue along with headaches when doing close work. A comprehensive optometric examination will include testing for presbyopia.
To help you compensate for presbyopia, your optometrist can prescribe reading glasses, bifocals, trifocals or contact lenses. Since presbyopia can complicate other common vision conditions like nearsightedness, farsightedness and astigmatism, your optometrist will determine the specific lenses to allow you to see clearly and comfortably. You may only need to wear your glasses for close work like reading, but you may find that wearing them all the time is more convenient and beneficial for your vision needs.
Since the effects of presbyopia continue to change the ability of the crystalline lens to focus properly, periodic changes in your eyewear may be necessary to maintain clear and comfortable vision.
A cataract is a clouding of all or part of the normally clear lens within your eye, which results in blurred or distorted vision. Cataracts are most often found in persons over age 55, but they are also occasionally found in younger people.
No one knows exactly what causes cataracts, but it is known that a chemical change occurs within your eye to cause the lens to become cloudy. This may be due to advancing age, heredity or an injury or disease. Excessive exposure to ultraviolet radiation in sunlight, cigarette smoking or the use of certain medications are also risk factors for the development of cataracts. Although cataracts develop without pain or discomfort, there are some indications that a cataract may be forming. These include blurred or hazy vision, the appearance of spots in front of the eyes, increased sensitivity to glare or the feeling of having a film over the eyes.
A temporary improvement in near vision may also indicate formation of a cataract. Currently, there is no proven method to prevent cataracts from forming. During a comprehensive eye examination, your optometrist can diagnose a cataract and monitor its development and prescribe changes in eyeglasses or contact lenses to maintain good vision. If your cataract develops to the point that it affects your daily activities, your optometrist can refer you to an eye surgeon who may recommend surgery. During the surgery, the eye’s natural lens is removed and usually replaced with a plastic artificial lens. After surgery, you can return to your optometrist for continuing care.
Macular degeneration is the leading cause of blindness in America. It results from changes to the macula, a portion of the retina that is responsible for clear, sharp vision and is located at the back of the eye. As macular degeneration advances, a distorted, dark, or empty area often appears in the center of vision.Most people with macular degeneration have the dry form, for which there is no known treatment. The less common wet form may respond to laser procedures, if diagnosed and treated early. Some common symptoms are a gradual loss of ability to see objects clearly, distorted vision, a gradual loss of color vision and a dark or empty area appearing in the center of vision.
If you experience any of these, contact your doctor of optometry immediately for a comprehensive examination. Central vision that is lost to macular degeneration cannot be restored. However, low vision devices such as telescopic and microscopic lenses can be prescribed to make the most out of remaining vision. Recent research indicates certain vitamins and minerals may help prevent or slow the progression of macular degeneration. Ask your doctor of optometry about these. After age 60, an annual, comprehensive eye examination is an important to maintain eye health.
Glaucoma is an eye disease in which the internal pressure in your eyes increases enough to damage the nerve fibers in your optic nerve and cause vision loss. The increase in pressure happens when the passages that normally allow fluid in your eyes to drain become clogged or blocked. The reasons that the passages become blocked are not known.
Noticeable symptoms of glaucoma may be a gradual loss of side vision (above) or blurred vision (below).Glaucoma is one of the leading causes of blindness in the U.S. It most often occurs in people over age 40. People with a family history of glaucoma, African Americans, and those who are very nearsighted or diabetic are at a higher risk of developing the disease.
The most common type of glaucoma develops gradually and painlessly, without symptoms. A rarer type occurs rapidly and its symptoms may include blurred vision, loss of side vision, seeing colored rings around lights and pain or redness in the eyes.
Glaucoma cannot be prevented, but if diagnosed and treated early, it can be controlled. Vision lost to glaucoma cannot be restored. That is why the American Optometric Association recommends annual eye examinations for people at risk for glaucoma (your doctor may, depending on your condition, recommend more frequent examinations). A comprehensive optometric examination will include a tonometry test to measure the pressure in your eyes; an examination of the inside of your eyes and optic nerves; and a visual field test to check for changes in central and side vision.
The treatment for glaucoma includes prescription eye drops and medicines to lower the pressure in your eyes. In some cases, laser treatment or surgery may be effective in reducing pressure.
The tears your eyes produce are necessary for overall eye health and clear vision. Dry eye means that your eyes do not produce enough tears or that you produce tears which do not have the proper chemical composition. Often, dry eye is part of the natural aging process. It can also be caused by blinking or eyelid problems, medications like antihistamines, oral contraceptives and antidepressants, a dry climate, wind and dust, general health problems like arthritis or Sjogren’s syndrome and chemical or thermal burns to your eyes. If you have dry eye, your symptoms may include irritated, scratchy, dry, uncomfortable or red eyes, a burning sensation or feeling of something foreign in your eyes and blurred vision.
Excessive dry eyes may damage eye tissue, scar your cornea (the front covering of your eyes) and impair vision and make contact lens wear difficult. If you have symptoms of dry eye, see your optometrist for a comprehensive examination. Dry eye cannot be cured, but your optometrist can prescribe treatment so your eyes remain healthy and your vision is unaffected. Some treatments that your optometrist might prescribe include blinking more frequently, increasing humidity at home or work, using artificial tears and using a moisturizing ointment, especially at bedtime. In some cases, small plugs are inserted in the corner of the eyes to slow tear drainage. Sometimes, surgical closure of the drainage ducts may be recommended.
Spots (often called floaters) are small, semi-transparent or cloudy specks or particles within the vitreous, the clear, jelly-like fluid that fills the inside of your eyes. They appear as specks of various shapes and sizes, threadlike strands or cobwebs. Since they are within your eyes, they move as your eyes move and seem to dart away when you try to look at them directly.
Spots are often caused by small flecks of protein or other matter trapped during the formation of your eyes before birth. They can also result from deterioration of the vitreous fluid, due to aging; or from certain eye diseases or injuries. Most spots are not harmful and rarely limit vision. But, spots can be indications of more serious problems, and you should see your optometrist for a comprehensive examination when you notice sudden changes or see increases in them. By looking in your eyes with special instruments, your optometrist can examine the health of your eyes and determine if what you are seeing is harmless or the symptoms of a more serious problem that requires treatment.
Astigmatism is a vision condition that occurs when the front surface of your eye, the cornea, is slightly irregular in shape. This irregular shape prevents light from focusing properly on the back of your eye, the retina. As a result, your vision may be blurred at all distances.
People with severe astigmatism will usually have blurred or distorted vision, while those with mild astigmatism may experience headaches, eye strain, fatigue or blurred vision at certain distances.
Most people have some degree of astigmatism. A comprehensive optometric examination will include testing to diagnose astigmatism and determine the degree.
Almost all levels of astigmatism can be optically corrected with properly prescribed and fitted eyeglasses and/or contact lenses.
Corneal modification is also a treatment option for some patients.
Lazy eye, or amblyopia, is the loss or lack of development of central vision in one eye that is unrelated to any eye health problem and is not correctable with lenses. It can result from a failure to use both eyes together. Lazy eye is often associated with crossed-eyes or a large difference in the degree of nearsightedness or farsightedness between the two eyes. It usually develops before age six and it does not affect side vision.
Symptoms may include noticeably favoring one eye or a tendency to bump into objects on one side. Symptoms are not always obvious.
Treatment for lazy eye may include a combination of prescription lenses, prisms, vision therapy and eye patching. Vision therapy teaches the two eyes how to work together, which helps prevent lazy eye from reoccurring.
Early diagnosis increases the chance for a complete recovery. This is one reason why the American Optometric Association recommends that children have a comprehensive optometric examination by the age of six months and again at age three. Lazy eye will not go away on its own. If not diagnosed until the pre-teen, teen or adult years, treatment takes longer and is often less effective.
Crossed-eyes (strabismus) occurs when one or both of your eyes turns in, out, up or down. Poor eye muscle control usually causes crossed-eyes. This misalignment often first appears before age 21 months but may develop as late as age six. This is one reason why the American Optometric Association recommends a comprehensive optometric examination before six months and again at age three.
There is a common misconception that a child will outgrow crossed-eyes. This is not true. In fact, the condition may get worse without treatment.
Treatment for crossed-eyes may include single vision or bifocal eyeglasses, prisms, vision therapy, and in some cases, surgery. Vision therapy helps align your eyes and solves the underlying cause of crossed-eyes by teaching your two eyes to work together. Surgery alone may straighten your eyes, but unless your eye muscle control is improved, your eyes may not remain straight.
If detected and treated early, crossed-eyes can often be corrected with excellent results.
Diabetes is a disease that interferes with the body’s ability to use and store sugar and can cause many health problems. One, called diabetic retinopathy, can weaken and cause changes in the small blood vessels that nourish your eye’s retina, the delicate, light sensitive lining of the back of the eye. These blood vessels may begin to leak, swell or develop brush-like branches.
Blurred central or side vision (left, blurred side vision) or a blind spot in central vision (below) may indicate diabetic retinopathy.
The early stages of diabetic retinopathy may cause blurred vision, or they may produce no visual symptoms at all. As the disease progresses, you may notice a cloudiness of vision, blind spots or floaters.
If left untreated, diabetic retinopathy can cause blindness, which is one reason why it is important to have your eyes examined regularly by your doctor of optometry. This is especially true if you are a diabetic or if you have a family history of diabetes.
To detect diabetic retinopathy, your optometrist can look inside your eyes with an instrument called an ophthalmoscope that lights and magnifies the blood vessels in your eyes. If you have diabetic retinopathy, laser and other surgical treatments can be used to reduce its progression and decrease the risk of vision loss. Early treatment is important because once damage has occurred, the effects are usually permanent.
If you are a diabetic, you can help prevent diabetic retinopathy by taking your prescribed medication as instructed, sticking to your diet, exercising regularly, controlling high blood pressure and avoiding alcohol and smoking.
November is National Diabetes Month. Members of the American Optometric Association are joining with members of other health care organizations in an effort to prevent blindness in Americans with diabetes. If you or a member of your family has not received a dilated eye examination in the past year, you should contact your optometrist for an appointment. If you do not have an optometrist, call 1-800-262-3947 for the names of doctors in your area.
During the infant and toddler years, your child has been developing many vision skills and has been learning how to see. In the preschool years, this process continues, as your child develops visually guided eye-hand-body coordination, fine motor skills and the visual motor skills necessary to learn to read.
As a parent, you should watch for signs that may indicate a vision development problem, including a short attention span for the child’s age; difficulty with eye-hand-body coordination in ball play and bike riding; avoidance of coloring and puzzles and other detailed activities.
There are everyday things that you can do at home to help your preschooler’s vision develop as it should.
These activities include reading aloud to your child and letting him or her see what you are reading; providing a chalkboard, finger paints and different shaped blocks and showing your child how to use them in imaginative play; providing safe opportunities to use playground equipment like a jungle gym and balance beam; and allowing time for interacting with other children and for playing independently.
By age three, your child should have a thorough optometric eye examination to make sure your preschooler’s vision is developing properly and there is no evidence of eye disease. If needed, your doctor can prescribe treatment including glasses and/or vision therapy to correct a vision development problem.
Here are several tips to make your child’s optometric examination a positive experience: 1) Make an appointment early in the day. Allow about one hour. 2) Talk about the examination in advance and encourage your child’s questions. 3) Explain the examination in your child’s terms, comparing the E chart to a puzzle and the instruments to tiny flashlights and a kaleidoscope.
Unless your doctor of optometry advises otherwise, your child’s next eye examination should be at age five. By comparing test results of the two examinations, your optometrist can tell how well your child’s vision is developing for the next major step…into the school years.
A good education for your child means good schools, good teachers and good vision. Your child’s eyes are constantly in use in the classroom and at play. So when his or her vision is not functioning properly, learning and participation in recreational activities will suffer.
The basic vision skills needed for school use are:
- Near vision. The ability to see clearly and comfortably at 10-13 inches.
- Distance vision. The ability to see clearly and comfortably beyond arm’s reach.
- Binocular coordination. The ability to use both eyes together.
- Eye movement skills. The ability to aim the eyes accurately, move them smoothly across a page and shift them quickly and accurately from one object to another.
- Focusing skills. The ability to keep both eyes accurately focused at the proper distance to see clearly and to change focus quickly.
- Peripheral awareness. The ability to be aware of things located to the side while looking straight ahead.
- Eye/hand coordination. The ability to use the eyes and hands together.
If any of these or other vision skills is lacking or not functioning properly, your child will have to work harder. This can lead to headaches, fatigue and other eyestrain problems. As a parent, be alert for symptoms that may indicate your child has a vision or visual processing problem. Be sure to tell your optometrist if your child frequently:
- Loses their place while reading
- Avoids close work
- Holds reading material closer than normal
- Tends to rub their eyes
- Has headaches
- Turns or tilts head to use one eye only
- Makes frequent reversals when reading or writing
- Uses finger to maintain place when reading
- Omits or confuses small words when reading
- Consistently performs below potential
Since vision changes can occur without you or your child noticing them, your child should visit the optometrist at least every two years, or more frequently, if specific problems or risk factors exist. If needed, the doctor can prescribe treatment including eyeglasses, contact lenses or vision therapy.Remember, a school vision or pediatrician’s screening is not a substitute for a thorough eye examination.
|Rigid gas-permeable (RGP)
Made of slightly flexible plastics that allow oxygen to pass through to the eyes
|Excellent vision…short adaptation period…comfortable to wear…correct most vision problems…easy to put on and to care for…durable with a relatively long life…available in tints (for handling purposes) and bifocals.||Require consistent wear to maintain adaptation…can slip off center of eye more easily than other types…debris can easily get under the lenses… requires office visits for follow-up care.|
|Daily-wear soft lenses
Made of soft, flexible plastic that allow oxygen to pass through to the eyes.
|Very short adaptation period…more comfortable and more difficult to dislodge than RGP lenses…available in tints and bifocals…great for active lifestyles.||Do not correct all vision problems…vision may not be as sharp as with RGP lenses…require regular office visits for follow-up care…lenses soil easily and must be replaced.|
Available for overnight wear in soft or RGP lenses.
|Can usually be worn up to seven days without removal.||Do not correct all vision problems…require regular office visits for follow-up care…increases risk of complication…requires regular monitoring and professional care.|
Soft lenses worn for an extended period of time, from one to six days and then discarded.
|Require little or no cleaning…minimal risk of eye infection if wearing instructions are followed…available in tints and bifocals…spare lenses available.||Vision may not be as sharp as RGP lenses…do not correct all vision problems…handling may be more difficult.|
Soft daily wear lenses that are replaced on a planned schedule, most often either every two weeks, monthly or quarterly.
|Require simplified cleaning and disinfection…good for eye health…available in most prescriptions.||Vision may not be as sharp as RGP lenses…do not correct all vision problems…handling may be more difficult.|
- Contact lenses move with your eye, allow a natural field of view, have no frames to obstruct your vision and greatly reduce distortions
- They do not fog up, like glasses, nor do they get splattered by mud or rain.
- Contact lenses do not get in the way of your activities.
- Many people feel they look better in contact lenses.
- Contact lenses, compared to eyeglasses, generally offer better sight.
Some Things To Remember About Contact Lenses
- Contact lenses, when compared with glasses, require a longer initial examination and more follow-up visits to maintain eye health; and more time for lens care.
- If you are going to wear your lenses successfully, you will have to clean and store them properly; adhere to lens wearing schedules; and make appointments for follow-up care.
- If you are wearing disposable or planned replacement lenses, you will have to carefully follow the schedule for throwing away used lenses.