a. People over age 50-
reduction in tears production, decreasing tear quality,
Corneal damage
b. Women approaching menopause
Hormonal changes. Reduction in tear production. Imbalance of the components in tears. Tears has 3 basic components
Lipid (oil) component (outer layer)- secreted by meibomian glands found in the lid margin. Contains fatty acids. Function by smoothening the tear film and preventing excessive evaporation of the watery layer.
Watery component (middle layer)- secreted by tear glands. Contains mostly water and a bit of electrolytes. Function by cleansing the eyes and washes away foreign bodies and irritants.
Mucus component (inner layer) – secreted by mucus cells on the conjunctival surface. Acts by attracting (holding on to the water layer). Also protects the surface of the cornea from damage.
c. People working in front of computers for long hours
When we concentrate (whether reading or computer activity), the blink rate is reduced. A normal blink rate is between 6-8 times a minute. It has been documented that when concentrating in near vision activity (e.g. reading, computer) the blink rate may be reduced to less than 1 per minute. This in effect causes the eyes to dry out resulting in ocular discomfort.
d. Travellers
Eyes dry out easily during in-flight because the in flight air is particularly dry. For people with dry eyes they should carry with them artificial tears.
e. People with degenerative diseases eg, ankylosing spondilytis, arthritis, Sjogren’s syndrome, etc
People suffering autoimmune disease such as rheumatoid arthritis, Sjogren syndrome has dry eyes that may be severe. These autoimmune disease affects the mucus membrane of the eyes as well as the tear producing glands resulting in some cases severe dry eyes. If normal tears supplement is insufficient they may require additional anti-inflammaroty treatment such as cyclosporine eye drops and surgical treatment such as occlusion of the punctum drainage ducts.
f. Contact lens wearers
Regular contact lens wearer complains of frequent dry eyes. Contact lens affects the tear film of the eye as well as reducing the oxygen availability to the cornea. This often results in micro breaks on the surface of the cornea resulting in discomfort and sensation of dryness. Tear supplements should be used if wearers have any discomfort. The tears supplement should be preservative free if used in conjunction with contact lens. However if the discomfort persists, contact lens used should be discontinued and patient should seek medical advice.
Patient may also consider contact lens made of newer material (silicone hydrogel) which allows higher oxygen permeability. This results in better comfort and less dry eyes symptoms.