What Are the Causes of Eye Diseases?

The eyes are one of the most valued and vulnerable parts of the human body. The eyes are susceptible to damage from injury as well as numerous diseases. Common eye diseases include glaucoma, diabetic retinopathy, cataracts, macular degeneration and conjunctivitis. When damage to the eyes occurs, it can result in temporary, permanent, full or partial loss of vision. Once vision is lost, it is often difficult or impossible to restore.

Glaucoma

• According to the American Optometric Association, glaucoma is the second leading cause of blindness in the United States. An individual's chance of developing glaucoma increases with age and family history. Glaucoma involves a loss of nerve tissue and damage to the optic nerve. Although the cause of glaucoma remains unknown, leading theories include increased fluid pressure in the eye and an inadequate blood supply to the nerve.

Diabetic Retinopathy

• Diabetic retinopathy is a diabetes-related complication. Diabetes can cause damage to the blood vessels in the retina. Fluid may get into an area of the retina called the macula which can cause blurred vision. New blood vessels may develop on the surface of the retina that are fragile and eventually leak. An individual's chance of developing a diabetic retinopathy increases the longer they have diabetes. The disease causes impaired vision and ultimately complete vision loss.

Cataracts

• A cataract is a cloudy area that develops over the eye and impairs vision. Cataracts form slowly over time and are most common in people over the age of 55. Cataracts form due to changes in the lens as a result of age. Cataracts can be caused by certain medications, nutrition deficiencies, diabetes, high alcohol consumption, UV radiation exposure and smoking.

Macular Degeneration

• Macular Degeneration involves problems with a part of the retina called the macula. The macula lies in the back of the eye and controlls the sharpness of vision. Macular degeneration can distort vision and cause color blindness. According to the National Eye Institute, macular degeneration is the leading cause of vision loss in Americans over 60 years of age.

Conjunctivitis

• Conjunctivitis is a very common, highly contagious eye disease commonly referred to as "pink eye." Conjunctivitis occurs when an infection develops in the conjunctiva. The conjunctiva is a thin layer of tissue lining the the interior of the eyelid. Conjunctivitis is usually caused by a viral or bacterial infection, irritants, cosmetics or chlorine from swimming pools. However, individuals can also develop conjunctivitis due to the existence of a foreign object in the eye such as contacts. Contact wearers should replace their contact lenses frequently in order to prevent conjunctivitis.