Your vision and the function of your eyes depend on more than just the shape of your eye and the eye lens. It also depends on the cornea's health, your tears, and how well they work. Many people do not think their tears are as helpful in facilitating sight.
But they are necessary for corneal health and light refraction into the eye. Dry eye syndrome is a condition that affects the quality or quantity of your tears and impacts your vision and eye health in many ways.
This is a condition that leads to poor lubrication of the eye surface, causing discomfort and impairing vision. Inadequate eye lubrication results from the condition's impact on the tear film, either through tear instability or insufficiency. When untreated, dry eye syndrome may cause damage and instability of the eye surface. To understand this better, knowing how the tear film works helps.
The tear film comprises three layers, the mucus or mucin, the aqueous, and the lipid or oily layers. The mucus layer is the lower layer produced by the sclera, or white of the eye. It helps spread the other layers evenly.
The lacrimal glands produce the aqueous layer, which is the middle layer. It is the largest in volume. It is primarily made up of water and contains nutrients that nourish the eye's surface. The third and topmost layer is the oily or lipid layer that covers the rest of the layers. It prevents the evaporation of the entire tear film.
Dry eye syndrome can develop for two main reasons, which can result from various causes. You can either have insufficient tears, dry eyes, unstable tears, or evaporative dry eyes.
When dry eye occurs due to insufficient tears, it is usually because the lacrimal glands are not producing enough of the aqueous layer. This leads to poor lubrication and nourishment of the eye surface.
This form is also known as decreased tear production or keratoconjunctivitis sicca and can occur for the following reasons:
Some medical conditions like rheumatoid arthritis, Sjogren's syndrome, lupus, and others
Side effects of medications like antidepressants, antihistamines, and blood pressure medications
Desensitization of the corneal nerve due to nerve damage, contact lens use, or laser eye surgery
This is the most common form of dry eye that people have. Unstable tears are a result of the lack or poor quality of the oily or lipid layer. This occurs when the meibomian glands responsible for producing the lipid layer malfunction. The malfunction could be a clogging of the glands or the production of poor-quality oils that fail to protect the tear film.
Despite the different forms of dry eye syndrome, the symptoms are the same. The most common symptoms include:
Scratchy, burning, or stinging feeling in the eye
Difficulty with nighttime driving
Gritty feeling or sensation of sand in the eye
Difficulty using contact lenses
Eye fatigue or strain