A healthy eye is hydrated by a film of tears. However, those who suffer from dry eye syndrome do not produce enough quality tears to keep the surface of the eye sufficiently moist throughout the day. The result is an irritated eye that may affect vision, and if left untreated, can cause damage to the cornea.
Dry eye syndrome is one of the most common ocular problems affecting adults today and can cause problems that range in severity from mildly irritating to debilitating. Dry eye syndrome is a general term that describes the state of the front of the eye in response to a breakdown in the natural layer of tears that coats the front of the eye, called the tear film. Normally, this is a stable layer of tears that not only provides the cornea and conjunctiva a healthy buffer from damage where it is constantly exposed to the air, but this interface between the tear film and the air is also responsible for a significant amount of the focusing power of the eye. When the tear film becomes unhealthy, it breaks down in various places on the cornea and conjunctiva, leading not only to symptoms of irritation, but also to unstable and intermittently changing vision.
It may sound like a contradiction but those with dry eye syndrome may notice their eyes water more than normal. This is because the unhealthy tear film and the irritation that comes from it stimulates the brain to produce excess tears to help counteract the irritation. However, this reflex tearing is simply insufficient to correct the overall problem. Other symptoms of dry eye syndrome include:
- Sandy or gritty feeling
- Scratchy or foreign body sensation
- Frequent blinking
- Matting or caking of the eyelashes (usually worse upon waking)
- Blurry or fluctuating vision (made worse when reading, using a computer, watching television, driving, etc.)
- Light sensitivity
- Eye pain and/or headache
- Heavy eye lids
- Eye fatigue