Dry eyes are caused by a lack of adequate tears. Your tears are a complex mixture of water, fatty oils, and mucus.
This mixture helps make the surface of your eyes smooth and clear, and it helps protect your eyes from infection.
What are the Symptoms of Dry Eyes?
For some people, the cause of dry eyes is an imbalance in the composition of their tears. Other people don't produce enough tears to keep their eyes comfortably lubricated. Eyelid problems, medications and other causes, such as environmental factors, also can lead to dry eyes or poor tear quality.
Signs and symptoms, which usually affect both eyes, may include:
- A stinging, burning or scratchy sensation in your eyes
- Stringy mucus in or around your eyes
- Increased eye irritation from smoke or wind
- Eye fatigue
- Sensitivity to light
- Eye redness
- A sensation of having something in your eyes
- Difficulty wearing contact lenses
- Periods of excessive tearing
- Blurred vision, often worsening at the end of the day or after focusing for a prolonged period
Could Excessive Tears Actually Mean Dry Eyes?
Sometimes, a person with a dry eye will have excess tears running down the cheeks, which may seem confusing. This happens when the eye isn't getting enough lubrication. The eye sends a distress signal through the nervous system for more lubrication. In response, the eye is flooded with tears to try to compensate for the underlying dryness. However, these tears are mostly water and do not have the lubricating qualities or the rich composition of normal tears. They will wash debris away, but they will not coat the eye surface properly.