Public Information

Frequently Asked Questions

Below are some of the most frequently asked questions posed to ophthalmologists.  The answers are intended as general summaries of typical conditions and illnesses of the eye. For specific personal information, please consult your ophthalmologist or use our Member Directory to locate one in your area.

FAQs about eyes

On occasion, I see little wavy lines or dots that seem to swim in my eyes. What is this, and should I be concerned?
What you are describing could be either floaters or flashes, both of which might be an indication of a quite serious problem, or it could be nothing! Floaters are tiny clumps of cells in the clear jelly-like fluid (the vitreous gel) inside your eye that cast shadows on the retina, the part of the eye that allows us to see. Sometimes floaters resemble dots, circles, clouds, or cobwebs. Flashes resemble streaks of lightning or bursts of light, indicating that the vitreous gel is tugging on the retina. Floaters and flashes become more common as people age, and they should always be examined immediately by an ophthalmologist to rule out bleeding in the eye from a retinal tear--a critical problem that might lead to retinal detachment and loss of sight. Often floaters and flashes are more a nuisance than a serious problem, and they may fade with time, but if you notice new ones, always have an eye examination immediately to rule out the need for immediate surgery to repair tearing.
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What is glaucoma and can it cause blindness?
While glaucoma is the second leading cause of blindness in the United States, loss of sight from glaucoma is preventable, but only if detected early enough. Glaucoma is a disease of the optic nerve (the part of the eye that carries the images we see to the brain), caused when pressure in the eye builds up because the eye's usual drainage capability becomes blocked. Consequently, if the pressure inside the eye becomes too high, the optic nerve may become damaged, causing blind spots. If the glaucoma either has gone undetected for a while or the pressure increases rapidly, the entire nerve can be destroyed, and blindness results. Glaucoma can strike at any age, but at greatest risk are African Americans, people with a family history of glaucoma, those aged 40 or older, or anyone who suffered a serious eye injury. Most forms of glaucoma are painless, so early detection and treatment by your ophthalmologist are the keys to prevention. Treatment commonly consists of medicated eye drops, but laser surgery is beginning to be used as well.
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How are diabetes and blindness related?
One of the complications of diabetes that affects the eyes is called diabetic retinopathy, caused by deterioration of the blood vessels that nourish the retina. If these weakened vessels leak fluid or blood, they can damage or scar the retina and ultimately blur vision. About 60 percent of people with diabetes more than 15 years have some blood vessel damage in their eyes. However, only a small percentage of those people have serious vision problems, and even fewer ever become blind. Nonetheless, diabetic retinopathy is the leading cause of new blindness among adults in the U.S., and diabetics are approximately 25 times more prone to blindness than non-diabetics. Pregnancy and high blood pressure may worsen this condition in diabetic patients. The best protection against the progression of diabetic retinopathy is awareness of the risks of developing sight disturbances and having regular exams by an ophthalmologist. When treatment is necessary, the most common method is laser surgery to seal the leaking blood vessels.
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Can cataracts be removed by lasers?
Cataracts are cloudy areas in the lens of the eye--which is normally clear, letting light pass through. When cataracts are present, vision becomes hazy because light no longer passes through easily. If cataracts progress and become large and dense, they can be surgically removed in what is usually a safe, outpatient procedure. Cataract surgery is a personal choice and should be considered when cataracts cause enough loss of vision to interfere with daily activities. More than 1.4 million people have cataract surgery each year in the U.S., 95 percent without complications. A cataract can only be removed using surgical techniques, although cataract surgery by lasers is being done experimentally. Intraocular lens implants often replace the natural lens, and about one-fifth of people later develop a clouding in the lens area; in this situation, laser surgery is used to create a "window" to help restore clear vision. This may be the reason for the public's confusion about whether laser surgery is used for cataract removal! By the way, while cataracts are most common in the aging eye, they also occur in younger people and people with diabetes. Also, cataracts may develop slowly, or quickly, and at differing rates in each eye. Protection from excessive sunlight may help prevent, or slow, progression.
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When should an adult with diabetes first be seen by an eye care provider and how often should they be evaluated thereafter?
Although approximately 80% of Type 1 diabetics (i.e., insulin-dependent) have retinopathy after 15 years of disease, only about 25% have any retinopathy after 5 years. The prevalence of proliferative diabetic retinopathy (PDR) is less than 2% at five years and 25% by 15 years. For Type 2 diabetes (non-insulin-dependent), however, the onset date of diabetes is frequently not precisely known and thus more severe disease can be observed soon after diagnosis. Up to 3% of patients first diagnosed after age 30 (Type 2) can have clinically significant macular edema or high-risk PDR at the time of initial diagnosis of diabetes.

Thus, in patients over the age of 10, initial ophthalmic examination is recommended beginning 5 years after the diagnosis of Type 1 diabetes mellitus and upon diagnosis of Type 2 diabetes mellitus.

Even if there is no or minimal retinopathy, annual follow-up is required since 5-10% of patients with no retinopathy will develop retinopathy within one year and existing retinopathy will be exacerbated by a similar percentage. Extensive retinopathy can exist even without symptoms. This minimum annual follow-up requirement assumes no abnormal findings. Abnormal findings necessitate more frequent follow-up. Symptoms and findings which suggest a higher risk of complication and should trigger more rigorous follow-up include floaters, distortion of vision, difficulty with night vision or reading vision, poor systemic control, advanced nephropathy, and concurrent hypertension.
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Are there situations where a patient with diabetes should be evaluated more or less often?
Puberty and pregnancy can accelerate retinopathy progression. The onset of vision-threatening retinopathy is rare in children prior to puberty regardless of the duration of diabetes. However, if diabetes is diagnosed between the ages of 10 and 30, significant retinopathy may arise within six years of disease. However, there is as yet no published data demonstrating that there is a statistically significant increased risk of retinopathy at 5 versus 3 years after diabetes diagnosis in this age group.

Thus, the current recommendation is for initial ophthalmologic examination within 3-5 years after diagnosis of diabetes once patients are age 10 years of age or older.

Diabetic retinopathy can also become particularly aggressive during pregnancy in patients with diabetes. Ideally, patients with diabetes who are planning pregnancy should have a comprehensive eye examination within one year prior to conception. Patients who become pregnant should have a comprehensive eye examination in the first trimester of pregnancy. Close follow-up throughout pregnancy is indicated with subsequent examinations determined by the findings present at the first trimester examination. This guideline does not apply to women who develop gestational diabetes, because such individuals are not at increased risk of developing diabetic retinopathy.
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What is amblyopia?
Amblyopia or "lazy eye" is reduced vision in an eye due to a lack of normal visual development during childhood. An amblyopic eye that does not see well early in life does not develop normal vision even with glasses. Amblyopia affects 3-4% of children and usually involves one eye though rarely can involve both. It may be the result of needing a different spectacle prescription in each eye, an opacity such as a cataract, or misalignment of the eyes. After the first nine years of life, the visual system is usually fully developed and cannot be significantly changed. The best time to correct amblyopia is during infancy or early childhood.

The presence of amblyopia is not always easy to recognize. Children should have their vision tested by their pediatrician or ophthalmologist before the age of four or earlier if there is any "wandering" of the eyes. Children with a family history of amblyopia should be checked even earlier within the first two to three years of life. Failing a vision screening does not always mean there is amblyopia as vision is often improved back to normal by prescribing glasses.

Amblyopia is treated by patching the stronger eye to strengthen the weaker eye. Patching may vary from a few hours a day to almost the entire day depending upon the visual acuity. Sometimes drops are used instead of patching to blur the better eye if cooperation is a problem. If amblyopia is not treated, the weaker eye may permanently have poor vision which is uncorrectable with glasses. If the problem is detected early, patching can help to improve vision in most children.
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What is keratoconus?
The word "keratoconus" literally means "cone-shaped cornea." The normal cornea is the clear dome on the front of the eye. The cornea bends, or refracts, the incoming light to help focus it on the retina. In order for you to see clearly, the cornea must be perfectly smooth and round, much like the surface of a billiard ball.
In keratoconus, the cornea is shaped more like the end of a football. This abnormal curvature makes the image formed on the retina quite blurry.

We do not know the cause of keratoconus but keratoconus is more common in people who have eye allergies and rub their eyes a lot.

In patients with mild keratoconus, often just a pair of glasses is all that is needed.

If the cone shape becomes more severe, however, glasses will not correct the problem. It is then necessary to use rigid contact lenses. These lenses sit on the tip of the cone and--while they're in place--create an optically smooth round surface, so the patient can see.

If keratoconus becomes very severe, the cone protrudes quite a bit, and contact lenses can no longer stay in place or become very uncomfortable. At this stage,a corneal transplant would be very likely to help the condition. In a corneal transplant, most of the cone-shaped cornea is removed and replaced with a normal donor cornea from a deceased person. The success rate of corneal transplants for keratoconus is excellent: about 95%.

Not everyone who has keratoconus will progress through these stages and need a transplant. Many patients have very mild disease and require just glasses.
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Some Recent NEOS Public Education Projects

NEOS is dedicated to public health and education. The NEOS Public Health and Education Committee designs and executes campaigns to disseminate eye health information directly to the public and allied health professionals.

Glaucoma Awareness Billboard Campaign

Glaucoma is a disease of the optic nerve that is usually related to high eye pressure. It is sometimes referred to as the "silent blinder" because it is, until the end stage of the disease, asymptomatic. There is no pain or blurred vision until the disease is quite advanced. For this reason, and because it is common, glaucoma presents a public health challenge.

The Public Health and Education Committee of NEOS has campaigned to increase glaucoma awareness. With the help of a grant from the Clear Channel Corporation, over 100 billboards in Eastern Massachusetts called attention to the importance of glaucoma screening.

IFIS Awareness Project

“Intraocular Floppy Iris Syndrome” was described in 2005. It is the irregular behavior of the iris tissue during intraocular surgery related to systemic alpha-1 blockers commonly prescribed for benign prostatic hypertrophy (BPH). The iris may not dilate well preoperatively, may constrict intraoperatively, or may have poor muscle tone. The medication most commonly associated with IFIS is the selective apha-1 blocker Flomax (tamsulosin HCL). The surgery most commonly affected is cataract surgery.

NEOS members have authored articles to educate about the relationship between Flomax and cataract surgery. Since most Flomax prescriptions are written by primary care doctors, effort has been directed toward PCP’s and urologists. Dr. Brendan McCarthy of the NEOS Public Health and Education Committee writes to the American Urological Association:

“Communication between ophthalmologists and those prescribing medicines for BPH is important for protecting patient’s well being. If possible, we would recommend asking patients if they have been diagnosed with cataracts and if they are having vision problems before prescribing a selective alpha-blocker. This might help avoid the all too common occurrence of patients being started on selective alpha-blockers just prior to cataract surgery. For patients on a non-selective or other agent in whom BPH therapy is being advanced, a comprehensive eye exam by an ophthalmologist can help determine the time frame for cataract surgery if indicated.”