One of the most important determinants of clear vision, consistent vision, and eye comfort is a healthy, consistent, moist layer of tears in the eye. By contrast, if the amount or quality of tears is reduced, this can lead to both a decrease in eye comfort and a decrease in clarity of vision. Patients with dry eye syndrome may experience burning, stinging, the sensation that something is in the eye, stringy mucus in or around the eye, fluctuating vision, blurry vision, shadows to the side of letters, halos around lights, nighttime glare, sensitivity to light, eye fatigue, eye redness, difficulty with nighttime driving, difficulty with contact lenses, and other symptoms. At your eye exam our doctors may see a lower level of tears, irregular tears, tears that do not coat the eye well, tears that quickly evaporate, tears with insufficient amount or quality of oil, dry spots on the eye, blocked oil glands on the eyelid, thickened and cloudy oils, or oil and debris buildup on your eyelids.
Our doctors may notice these findings on your eye exam even if you do not experience the symptoms listed above. Some patients with dry eye syndrome do not even feel that their eyes are dry. In fact, one of the classic symptoms of dry eye is an eye that waters frequently. Consider this analogy. If your lips are dry and chapped enough the skin may crack. If you lick them with your tongue they may become temporarily moist, but in reality when this moisture evaporates your lips are still dry. A dry eye is a chapped eye, and the small “cracks” on the eye can scatter light and lead to blurry, fluctuating vision. While there is no pill or cure to fix dry eye, there are strategies which, when applied consistently over time, can help you manage it.
Causes – 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. For some people, the cause of dry eyes is decreased tear production. For others it’s increased tear evaporation and an imbalance in the makeup of your tears.
Dry eyes can occur when you’re unable to produce enough tears. Common causes of decreased tear production include:
Common causes of increased tear evaporation include:
The tear film has three basic layers: oil, water and mucus. Problems with any of these layers can cause dry eyes. For example, the oil film produced by small glands on the edge of your eyelids (meibomian glands) might become clogged. Blocked meibomian glands are more common in people with inflammation along the edge of their eyelids (blepharitis), rosacea or other skin disorders.
Risk factors – factors that make it more likely that you’ll experience dry eyes include:
Complications – people who have dry eyes may experience these complications: