Science Journal

How Eyes get Dry

I went to an ophthalmologist's store to buy a contact lens because I badly wanted to. Actually, I am a basketball player at my university and I want to improve the accuracy of my shooting skills. Without my eyeglass, I cannot tell how close or far I am from the ring because I have a blurry vision. I cannot determine the probable force I am going to exert in shooting the ball to the ring accurately. So, when I let my eyes be checked by an ophthalmologist, he suggested that I should buy the monthly disposable contact lens, not the long-term contact lens because my eyes are dry. He asked me if I stare on a computer for too long and frequently, I nodded and told him I am an IT student. I wanted to asked how eyes got dry but the doctor seems impatient and not in a mood to communicate with human beings. I hypothesized less blinking could lead to dry eyes because I think blinking lubricates the eyes. So, I just googled if my guess is correct and it was. Also, I learned how staring the computer screen for too long can cause dry eyes.

Dry eyes occur when tears are incapable of producing adequate lubrication and moisture for the eyes caused with many various reasons. Lack of lubrication and moisture would lead to eye irritation, inflammation and even damaging the surface of the eye. A normal tear composed of three vital components, lipid (the oily component), aqueous (watery component), mucin (mucous-like component). Each of them is produced on different glands on or near the eye. The meibomian glands produce the oily component in the eyelids. The lacrimal gland located behind the outer aspect of the upper eyelid, produce the watery component. And lastly, the mucin component is created by goblet cells in the conjunctiva that covers the white of the eye (sclera). This mixture helps the surface of the eyes smooth and clear, and also protects the eyes from infection through blinking. Excess fluid drains through the tear ducts into the nose.

Sometimes, dry eyes create too many tears due to lack of moisture which irritates the eyes. It sends a distress signal to the nervous system for more lubrication, thus the body sends a flood of tears as a protective mechanism. So, watery eyes can be a symptom of acquiring this eye condition. But this "reflex tearing" cannot stay long enough to correct the underlying dry eye condition.

Since the components of the tears are produced on different locations in the eye, it can result in instability and dry eyes. Below are the different categories of dry eyes.

Evaporative dry eye or Meibomian gland dysfunction: The meibomian glands do not secrete enough oil thereby the tear film evaporates quickly.

Aqueous Deficiency Dry Eye: when lacrimal glands fail to produce enough watery fluid to keep the eyes moistened.

Decreased tear production: People older than 50 experience this dry eyes condition because as we get older the tear production diminish. Unfortunately, lack of tears is more common in women especially when hormonal changes occur due to pregnancy, using birth control pills or menopause. Another factor is the person has certain medical conditions such as diabetes, lupus, thyroid disorders, rheumatoid arthritis, scleroderma, Sjogren's syndrome. Deficient of vitamin A, wearing contact lens, taking certain medications like antihistamines, decongestants, hormone replacement therapy, antidepressants, and drugs for HBP, acne, birth control, and Parkinson's disease, or underwent laser eye surgery (but the effect is temporary) also reduces tear production. It's so sad to know that wearing contact lens cause dry eyes which I intended to use but the eye expert did allow me to use it, but I just need to buy eye drops to keep my eyes lubricated. Additional expenses. Sigh. 

Increased tear evaporation: Evaporation occurs when you are in a windy, dry, and smoky area. Concentrating on a particular task like reading, driving or working at a computer which makes you blink less often also induce increased tear evaporation. If not, perhaps there is a problem with your eyelid.

Imbalance in tear composition: The oil film producer, meibomian glands are clogged which is commonly found in people with inflammation along the edge of their eyelids, rosacea, or other skin disorders.

Consequently, without adequate tears, the risk of acquiring eye infection increases because tears protect the surface of the eyes from infection. If left untreated, severe dry eyes may lead to inflammation, scratches the corneal surface, and vision problems.

For prevention, avoid putting your eyes directly on the aircon, fans, hair dryers or letting your friend blow your eyes. Better request your friend to blow some area in your body, not your eyes. Or wear protective eyewear such as eyeglass to block wind and dry air. If you are doing long tasks which require visual concentration such as reading or doing something on a computer,  take a break. Close your eyes for a few minutes, make sure you do not fall asleep or blink repeatedly for a few seconds to spread tears over your eyes. If you are in a desert or riding in an airplane where altitudes are high and air are extremely dry, frequently close your eyes for a few minutes to minimize the evaporation of your tears. Or better close your eyes and hire someone who doesn't have dry eyes to be your eyes. Stop smoking and avoid smokes because smoke worsens dry eyes symptoms. If you have chronic dry eyes, use eyedrops to keep your eyes lubricated.

Well, wish me luck. I hope I could successfully put the contact lens on my eyes safely and would feel comfortable wearing it.