Therapeutic Eye Drops

The human eye has several mechanisms that protect its delicate, precision inner workings. When something moves quickly toward the eye, reflexes close it and cause the head to turn away. The eye blinks about 15,000 times every day. Each blink happens in about 300 to 400 milliseconds. Blinking wipes the surface of the eye clean and replenishes the moisture there.

Tears are not simply water; they contain about 15 different substances that come from three main types of glands. The lipid or fat component of tears prevents them from evaporating too quickly, and keeps them in the eye, much like oil on water calms it. The aqueous component is largely water, and contains proteins and other substances that disinfect the cornea. The mucus component helps keep the other substances mix well and spread evenly over the eye.

There are three types of tears. Basal tears are the highest quality and should always be present in healthy eyes. Reflex tears are the eye's way of ridding itself of contaminants. Psychic tears are a response to emotional disturbances. Reflex and psychic tears contain higher amounts of water and are not suitable for fully lubricating the eye.

If a person has dry eyes because of an insufficiency of basal tears, reflex or psychic tears will not be enough to keep the eye moist over its entire surface. Often therapeutic eye drops are required to moisten the eye. Sometimes a person will have dry eyes because of surgery such as photorefractive keratectomy or contact lens use or extensive computer use. Often simple over the counter therapeutic eye drops will be enough to remedy the problem. These drops usually contain a lubricant such as glycerin, a preservative and a water base. If more advanced moistening is needed perhaps it would be a good idea to see your doctor about medicated eye drops.