Opthalomology

The cornea and lens of your eye helps you focus. Refractive errors are vision problems that happen when the shape of the eye keeps you from focusing well. The cause could be the length of the eyeball (longer or shorter), changes in the shape of the cornea, or aging of the lens.


Four common refractive errors ar

  • Myopia, or nearsightedness - clear vision close up but blurry in the distance
  • Hyperopia, or farsightedness - clear vision in the distance but blurry close up
  • Presbyopia - inability to focus close up as a result of aging
  • Astigmatism - focus problems caused by the cornea

The most common symptom is blurred vision. Other symptoms may include double vision, haziness, glare or halos around bright lights, squinting, headaches, or eye strain.

Glasses or contact lenses can usually correct refractive errors. Laser eye surgery may also be a possibility.

A cataract is a clouding of the lens in your eye. It affects your vision. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.


A cataract can occur in either or both eyes. It cannot spread from one eye to the other. Common symptoms are

  • Blurry vision
  • Colors that seem faded
  • Glare - headlights, lamps or sunlight may seem too bright. You may also see a halo around lights.
  • Not being able to see well at night
  • Double vision
  • Frequent prescription changes in your eye wear

Cataracts usually develop slowly. New glasses, brighter lighting, anti-glare sunglasses or magnifying lenses can help at first. Surgery is also an option. It involves removing the cloudy lens and replacing it with an artificial lens. Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataracts.

Glaucoma is a group of diseases that can damage the eye's optic nerve. It is a leading cause ofblindness in the United States. It usually happens when the fluid pressure inside the eyes slowly rises, damaging the optic nerve. Often there are no symptoms at first. Without treatment, people with glaucoma will slowly lose their peripheral, or side vision. They seem to be looking through a tunnel. Over time, straight-ahead vision may decrease until no vision remains.

A comprehensive eye exam can tell if you have glaucoma. People at risk should get eye exams at least every two years. They include

  • African Americans over age 40
  • People over age 60, especially Mexican Americans
  • People with a family history of glaucoma

There is no cure, but glaucoma can usually be controlled. Early treatment can help protect your eyes against vision loss. Treatments usually include prescription eyedrops and/or surgery.

The retina is a layer of tissue in the back of your eye that senses light and sends images to your brain. In the center of this nerve tissue is the macula. It provides the sharp, central vision needed for reading, driving and seeing fine detail.

Retinal disorders affect this vital tissue. They can affect your vision, and some can be serious enough to cause blindness. Examples are

  • Macular degeneration - a disease that destroys your sharp, central vision
  • Diabetic eye disease
  • Retinal detachment - a medical emergency, when the retina is pulled away from the back of the eye
  • Retinoblastoma - cancer of the retina. It is most common in young children.
  • Macular pucker - scar tissue on the macula
  • Macular hole - a small break in the macula that usually happens to people over 60

Macular degeneration, or age-related macular degeneration (AMD), is a leading cause of vision loss in Americans 60 and older. It is a disease that destroys your sharp, central vision. You need central vision to see objects clearly and to do tasks such as reading and driving.


AMD affects the macula, the part of the eye that allows you to see fine detail. It does not hurt, but it causes cells in the macula to die. There are two types: wet and dry. Wet AMD happens when abnormal blood vessels grow under the macula. These new blood vessels often leak blood and fluid. Wet AMD damages the macula quickly. Blurred vision is a common early symptom. Dry AMD happens when the light-sensitive cells in the macula slowly break down. Your gradually lose your central vision. A common early symptom is that straight lines appear crooked.


Regular comprehensive eye exams can detect macular degeneration before the disease causes vision loss. Treatment can slow vision loss. It does not restore vision.

If you have diabetes, your blood glucose, or blood sugar, levels are too high. Over time, this can damage your eyes. The most common problem is diabetic retinopathy. It is a leading cause of blindness in American adults.

Your retina is the light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. Diabetic retinopathy damages the tiny blood vessels inside your retina.


You may not notice it at first. Symptoms can include

  • Blurry or double vision
  • Rings, flashing lights, or blank spots
  • Dark or floating spots
  • Pain or pressure in one or both of your eyes
  • Trouble seeing things out of the corners of your eyes

Treatment often includes laser treatment or surgery, with follow-up care


Two other eye problems can happen to people with diabetes. A cataract is a cloud over the lens of your eye. Surgery helps you see clearly again. Glaucoma happens when pressure builds up in the eye, damaging the main nerve. Eye drops or surgery can help. If you have diabetes, you should have a complete eye exam every year. Finding and treating problems early may save your vision.

Conjunctivitis is the medical name for pink eye. It involves inflammation of the outer layer of the eye and inside of the eyelid. It can cause swelling, itching, burning, discharge, and redness. Causes include

Your retina is the light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. Diabetic retinopathy damages the tiny blood vessels inside your retina.


You may not notice it at first. Symptoms can include

  • Bacterial or viral infection
  • Allergies
  • Substances that cause irritation
  • Contact lens products, eye drops, or eye ointments

Pinkeye usually does not affect vision. Infectious pink eye can easily spread from one person to another. The infection will clear in most cases without medical care, but bacterial pinkeye needs treatment with antibiotic eye drops or ointment.