The front surface of the eye needs to stay properly hydrated for proper eye health, comfort, and good vision. With each blink, the eyelids spread a tear film across the front surface of the eye. This tear film is made up of several layers – an oily outer layer, a watery middle layer and a mucus-like inner layer. If any of these layers becomes compromised, eye health, comfort and vision can be affected.
Dry eyes can result from many factors. Normal changes that occur with aging can result in dryness. Environmental factors such as wind, dust and dry air can speed the tear’s evaporation rate. Medications such as those used to treat acne and allergies can have side effects causing or contributing to dry eyes. Incomplete blinking, infrequent blinking, or eyelid irregularity may cause inadequate wetting of the eye.
A person with dry eyes may experience discomfort, tiredness, blurred vision, red and irritated looking eyes. Patients may actually complain of watery eyes. As the eye becomes dry and irritated, the sensation of dryness is detected. The tear gland responds by producing excess tears. These tears are often not of normal oil, water, and mucus quality but are higher in water content. This watered down tear results from the initial feeling of dryness.
An eye doctor can detect this condition during an eye examination. The tear quality and quantity can be assessed with the use of a microscope and special dyes used to better see the tear film. The time the tear film remains intact following a blink helps indicate if the rate of tear evaporation is too quick, or if the blink rate is too slow. Tear volume can also be measured and determined to be a factor in dry eye symptoms.
Initial treatment of dry eye is aimed at restoring hydration with the use of tear supplements called artificial tears. They give the eye an added boost of moisture, which may be all that is needed for some individuals. Environmental modifications such as redirecting fans and air conditioners away from the eye are advised. The use of a humidifier or the addition of plants may benefit the dry-eyed patient because tears last longer when the surrounding air is humid rather than dry. Diet modifications, such as increased intake of foods rich in omega three fatty acids, over time may lessen ocular dryness. Fish oil and flax seed oil are rich in omega three fatty acid. This oil is a component of the normal tear chemistry. Omega three fatty acid supplements are available in most grocery stores and nutrition centers. Aside from helping with dry eyes, they have also been shown to have other health benefits. After following these recommendations, persistent or severe ocular dryness may be treated medically through the use of low dose steroid eye drops. Steroids are anti-inflammatory agents. Inflammation of the eye surface leads to dryness, which in turn causes more inflammation. Other medications may help increase tear production, which is beneficial when inadequate tear production is a contributor to dry eyes. Small plugs may also be used to block the tear drainage canal through which tears escape. By keeping tears from escaping the surface of the eye, moisture can be maintained for a longer time.