Our eyes are the tools that we use to gather information from our environment. This information not only gives us pleasure but also guides our behavior.(1) We take our eyes for granted yet we value them so highly. Taking care of our eyes is critical and the importance of eye examinations cannot be over emphasized. Eye examinations often reveal signs of disease and ocular disorders. Regular examinations can also determine the effects of drugs that are either administered systemically or used directly in the eye itself.

The eyes are mounted in a prominent position on the head, and thus are vulnerable to a variety of disturbances. Our vision can be damaged by trauma, exposure, or infection and there are many diseases of the eye including glaucoma, cataracts, or retinal detachment. Other diseases may have ocular symptoms, as do some of the neurologic diseases affecting areas of the cortex, thalamus, and brainstem that are devoted to visual perception or to the execution of eye movements. Although it may be determined that a patient requires specialized eye care, the initial examination and assessment of visual acuity, pupils, eye movements, and visual fields, can be done by a general practitioner.

A cataract is a clouding of the lens sufficient to reduce vision. Most cataracts develop slowly as a result of the aging process, and lead to a gradual reduction in vision. The only treatment is surgical extraction of the opacified lens. Remarkable technical innovations have made it possible to remove the cataract while leaving the lens capsule intact. A plastic or silicone lens is then placed in the empty lens capsule, replacing the natural lens, and most generally leading to improved sight in most patients.

Other physical conditions also affect vision. For example if a person has a stroke that affects the right optic pathway, he/she may develop hemianopsia, or defective vision/blindness in half of the visual field. If the stroke affects the right side, the patient's left visual field is affected since the image projected by the eye reverses the field. The term used to describe this condition is left homonymous hemianopsis. The patient would only see the right half of his environment, since the right optic tract impairment has affected his ability to see the left side of his visual field. Using visual field defects can help vastly in attempting to localize the point of a lesion.

The FDA has done a review to determine which ophthalmic conditions may occur that are self-treatable. It must be remembered, though, that each of these may potentially be serious enough to seek treatment by a physician or ophthalmologist. If patients experience eye pain, changes in vision, continued redness, or irritation in the eye, or if the condition worsens or persists, patients must discontinue use of nonprescription products and see a physician. Self-treatable conditions include:

• Dry eye
• Loose foreign material
• Redness caused by minor eye irritation
• Discomfort caused by minor eye irritation
• Corneal edema
• Ophthalmic allergic conjunctivitis

Dry eye refers to a syndrome resulting from many conditions that produce abnormalities of tear film flow and/or stability rather than denoting a specific disease.(2) This condition can result from a number of circumstances. Tear production is also affected by total body hydration. Aqueous secretions such as tears and saliva may be compromised as the body conserves water to provide water to the cells of more vital organs.

Vitamin A deficiency is a major cause of childhood blindness in underdeveloped countries because vitamin A deficiency results in mucin deficiency.(3) The eye undergoes a loss of mucin-secreting goblet cells, resulting in an unstable tear film that causes dry patches on the eye. If not corrected this can lead to more<