Detecting Eye Diseases and Conditions

Medically Reviewed by Whitney Seltman, OD on August 17, 2022
Written by WebMD Editorial Contributors
9 min read

As our population ages, vision loss from eye diseases is increasing.

According to the National Eye Institute (NEI) and the CDC:

  • About 4.2 million Americans ages 40 or older are blind or have low vision. This is about 1 in every 28 people. By 2050, t the number of people with visual impairment or blindness in the United States is expected to double to more than 8 million.

NEI has identified the most common eye diseases in people over age 40 as:

  • Age-related macular degeneration
  • Cataracts
  • Diabetic eye disease
  • Glaucoma

To catch eye conditions early and help prevent vision loss, you should get a baseline eye exam when you are 40. If you are at high risk for an eye problem, yearly visits are recommended. If there are no issues, you should then see your doctor every 2 to 4 years until you are 54. Afterwards, visits should be more frequent - every 1 to three 3 years. By the time you reach 65, consider visits every 1 to 2 years.

Here's what you should know about these threats to your eyesight.

Age-related macular degeneration (AMD) damages, then destroys, central vision, your "straight-ahead," finely detailed vision. This eye disease takes two forms, dry and wet. About 90% of AMD cases are dry. The remaining 10% are wet, a more advanced form. Wet AMD is more damaging, causing about 90% of serious vision loss. Injections of medications that help to prevent the growth of leaky blood vessels in the eye are the preferred treatment for this form of AMD. 

Starting with the highest risk, people who:

  • Are over age 60
  • Smoke
  • Have a family history of AMD
  • Are white (Caucasian) and female
  • Have high blood pressure (hypertension)
  • Are obese

AMD is painless. It may worsen slowly or rapidly. Dry AMD may affect central vision within a few years. Wet AMD can cause sudden and dramatic changes in vision. In either case, early detection and treatment are key to slowing vision loss. See your eye doctor right away if you notice:

  • Straight lines appearing wavy, a symptom of wet AMD
  • Blurred central vision, the most common dry AMD symptom
  • Trouble seeing things in the distance
  • Difficulty seeing details, like faces or words on a page
  • Dark or "blank" spots blocking your central vision

Wet AMD treatment may include:

  • Special drug injections (by far the most common treatment)
  • Laser surgery
  • Photodynamic therapy

Dry AMD treatment is aimed at monitoring or slowing the progression of the disease. Vision loss from advanced dry AMD cannot be prevented. But taking certain dietary supplements may help stabilize the disease in some patients. One large study has shown that taking high doses of the antioxidants vitamin C, vitamin E, lutein, and zeaxanthin, along with zinc, may help slow AMD progression in cases of:

  • Intermediate AMD
  • High risk of progressing to advanced AMD
  • Advanced AMD in just one eye

However, the study showed that this regimen did not prevent AMD onset or slow its progression in early-stage disease.

These preventive steps may help keep AMD at bay:

  • Eat more leafy green vegetables and fish.
  • Taking AREDS 2  (Age-Related Eye Disease Study 2)or other special vitamin supplements recommended by your doctor
  • Maintain a healthy weight and exercise regularly.
  • Don't smoke.
  • Check your blood pressure regularly. Get treatment if your blood pressure is too high.

A cataract is an eye condition in which the eye's normally clear lens becomes cloudy. It eventually occurs in both eyes but may be more noticeable in one eye first. Since less light passes through a cloudy lens, vision blurs. Cataracts are small at first and may not affect vision. But the denser they grow, the more they affect your vision.

Most cataracts are due to aging. Other risk factors include:

  • Diseases, like diabetes
  • Eye injury or trauma
  • Eye surgery for another problem
  • Inheritance or pregnancy-related causes (Babies can be born with cataracts or develop them in childhood.)
  • Overexposure of eyes to the sun's damaging ultraviolet (UV) rays
  • Smoking
  • Certain medications

The risk increases with age. Other risk factors for cataracts include:

  • Environmental -- such as overexposure to sunlight
  • Lifestyle -- including smoking and alcohol use
  • People who have certain diseases -- including diabetes

The most common cataract symptoms include:

For early cataracts, these steps may help:

  • Getting a new eyeglass or contact lens prescription
  • Using brighter lighting
  • Using magnifying lenses
  • Wearing sunglasses

If cataracts interfere with everyday activities, your doctor will probably recommend surgery. Surgical cataract removal is one of the most common, safest, and most effective types of surgery done in the U.S. Delaying cataract surgery until it interferes with your quality of life is appropriate and won't harm your eyes.

If you choose surgery, you'll be referred to an ophthalmologist who can perform the surgery (if you don't already have a doctor you trust). During the procedure, the eye surgeon removes the cloudy lens and replaces it with an artificial clear lens. If both eyes need cataract surgery, surgery will generally be done one eye at a time separated by a time interval felt appropriate by your surgeon.

You may help delay cataract development by:

  • Avoiding overexposure to sunlight; wear wraparound sunglasses with ultraviolet protection and a wide-brimmed hat.
  • Not smoking

People with diabetes are at risk for developing several eye diseases:

Diabetic retinopathy is the most common eye disease in people with diabetes. It affects over 5 million Americans ages 18 and older. Usually both eyes develop the disease. Diabetic retinopathy progresses in four stages. The most severe is proliferative retinopathy.

Damaged blood vessels due to diabetic retinopathy can cause vision loss and blindness two ways:

  1. Fluid leaks into the center of the retina, called the macula. This area of the retina is where central vision takes place. The fluid causes the macula to swell, blurring vision.
  2. In proliferative retinopathy, new and abnormal blood vessels grow. These vessels blur vision by leaking blood into the center of the eye and causing scar tissue, and that can lead to retinal detachment.

Everyone with diabetes, type 1 and type 2, is at risk for diabetic eye disease. The longer you have diabetes, the more your risk grows. According to the National Eye Institute, up to 45% of Americans diagnosed with diabetes have some form of diabetic retinopathy.

One problem with identifying yourself as being at risk is that proliferative retinopathy and macular swelling can develop without any symptoms. Sometimes vision remains unaffected as the eye disease progresses. Nevertheless, your risk of eventual vision loss is high - one reason why routine eye exams are necessary.

Like diabetes, early symptoms of diabetic retinopathy may not be noticed for some time. Don't wait for symptoms to appear before taking action. If you've been diagnosed with diabetes, schedule a complete dilated eye exam with your eye doctor once a year, or more often if needed. If you delay treatment until vision is noticeably affected, it may be less effective.

See your eye doctor right away if you notice these symptoms:

  • Blurred vision. This is very common in people with diabetes who have unstable blood sugar levels, even without the presence of retinopathy.
  • "Floaters" that swim in and out of your vision in one eye that last longer than a few days. These may be ordinary harmless floaters, but if you have diabetes especially, floaters may be the sign of bleeding in the back of the eye. New floaters are always a reason for seeing an eye doctor -- especially when you have diabetes.

"Scatter" laser treatment (pan-retinal photocoagulation) is effective for treating new blood vessels before or after they begin to bleed. Severe bleeding may be treated with a surgical procedure (vitrectomy) by removing blood from the center of the eye.

"Focal" laser treatment may be done to stabilize vision. This therapy may reduce vision loss by up to 50%.

These laser treatments may reduce the risk of serious vision loss and blindness. But they cannot cure diabetic eye disease. They cannot bring back lost vision or prevent future vision loss.

Newly developed medications can be injected into the eye to treat the complications of diabetes.

More than a third of people with diabetes don't get proper vision care. This puts them at higher risk for blindness. If you have diabetes, be vigilant about eye and vision care. People with diabetes, even those without diagnosed eye disease, need to see their eye doctor once a year. Those with diabetic changes in their eyes need to be seen more frequently.

Keeping your blood sugar tightly controlled (as measured by both your blood sugar and hemoglobin A1C levels) and your blood pressure within the normal range both help. Always follow your doctor's recommendations regarding medication, diet, and exercise.

Glaucoma is a group of related eye diseases that can cause blindness. Many people who have it don't know it. That's because symptoms don't appear until glaucoma has already damaged the optic nerve. This nerve carries images from the eye to the brain. Glaucoma optic nerve damage is usually associated with an elevated pressure inside the eye (intraocular pressure).

The most common type of glaucoma is primary open-angle glaucoma. Its causes are not yet clearly understood. Glaucoma can also develop without an increase in eye pressure, called low-tension or normal-tension glaucoma.

Glaucoma can develop in anyone. However, people at increased risk include:

  • People over age 60
  • Mexican-Americans
  • African-Americans, especially those with high eye pressure, corneal thinness, or optic nerve problems
  • Anyone who has had a severe eye injury
  • People with certain medical conditions, such as diabetes
  • Anyone with a family history of glaucoma
  • A person who has increased eye pressure

Typically, glaucoma has no symptoms until the latest and most advanced stages when vision is just about gone. That’s why some people call glaucoma “the sneak thief of sight.” As this eye disease progresses, the person with glaucoma may notice progressive vision loss, including:

  • Blurry vision
  • Narrowed side (peripheral) vision
  • Problems focusing
  • A "halo" effect around lights (This is unusual and typically occurs at extreme eye pressures and acute glaucoma attacks.)

There is no cure for glaucoma. Once vision is lost, it cannot be restored. However, early detection and treatment of this eye disease can often protect you from severe vision loss.

Glaucoma treatment may include:

  • Eye drops or pills that help reduce pressure in the eye
  • Several kinds of laser treatments to decrease eye pressure or to compensate for narrow angle glaucoma
  • Surgery to create a new opening for fluid to drain from the eye

If you're taking medicine for glaucoma, take your medicine every day as directed. Remember, when you don’t take your medicine, your eye pressure increases -- and that may be silently causing permanent vision loss.

If you've lost some vision due to this eye disease, your eye doctor can refer you for low-vision services. Low-vision aids can help you make the most of your remaining vision.

The key to preventing glaucoma is to maintain normal eye pressure. What eye pressure level is "normal" for you? Only an eye doctor can determine this.

Have regular eye exams every 2 to 4 years until age 54 and hen every 1 to 3 years until 65. After that you should have an exam every 1 to 2 years.

Your eye doctor may notice high eye pressure or may determine that you are at high risk of developing glaucoma. In these cases, you may be asked to use eye drops or visit the doctor more often. In some people who are at risk for glaucoma, eye drop treatment can reduce the risk by about 50%. Reducing eye pressure is the only known way to slow or stop the progression of visual loss from glaucoma.