Dry eye disease (DED) is one of the most commonly occurring ocular conditions. Dry eye disease is estimated to affect 5% to 35% of the population; a higher incidence with age, more common among certain populations, and is influenced by environmental factors.
Environment
Sunny, dry, or windy weather, heaters, air conditioners and high altitudes increase the evaporation of tears from the surface of your eyes. You may experience dry eye symptoms while viewing television, computer screens, or while reading.
Tear Drainage
If you have too much tear drainage, or too little tear production, you may experience dry eye symptoms or related symptoms in the nose, throat and sinuses.
Poor Quality of Tears
Tears are made up of three layers: oil, water and mucus. Each component serves a function in protecting and nourishing the front surface of the eye. A smooth oil layer helps to prevent evaporation of the water layer, while the mucin layer functions in spreading the tears evenly over the surface of the eye. If the tears evaporate too quickly or do not spread evenly over the cornea due to deficiencies with any of the three tear layers, dry eye symptoms can develop.
Contact Lens Wear
Wearing contact lenses increases tear evaporation and related dry eye symptoms. Dryness may result in protein deposits on the contact lenses, eye irritation, pain, infection, or sensitivity to contact lens solutions. Dry eye symptoms are the number one reason people stop wearing contact lenses.
Aging
Tear production gradually decreases with age. At age 65 the tear glands produce about 40% of the lubricating tears they produced at age 18. Decreased tear production may cause eye irritation and excess tearing or watery eyes.
Medications
Tear production may be reduced if you take certain medications including: decongestants, antihistamines, betablockers, sleeping pills, anxiety medications, pain relievers, and diuretics. If you are taking any medication, ask the eye doctor if it contributes to your dry eye symptoms.