Introduction<br /><br />Dry eye is a common ocular condition that occurs when the eye is unable to maintain adequate lubrication. Insufficient tear production or poor tear quality can lead to ocular surface inflammation or damage to the protective tear film. Patients with dry eye often experience discomfort, including burning sensations or itching, in various situations such as air-conditioned environments or during prolonged use of computers and digital devices.<br /> <br />Tear Film and Pathophysiology<br /><br />The eye’s tear film consists of three layers:<br />1. Lipid layer (oils) – reduces tear evaporation.<br />2. Aqueous layer (water component) – provides hydration.<br />3. Mucin layer (mucus) – ensures uniform tear distribution over the ocular surface.<br /><br />Any dysfunction in one or more of these layers can lead to dry eye. Insufficient aqueous tear production, in particular, may result in a condition known as keratoconjunctivitis sicca.<br /> <br />Major Causes of Dry Eye<br />1. Aging – Tear production naturally declines with age.<br />2. Systemic and ocular diseases – Including allergic eye disorders, rheumatoid arthritis, thyroid dysfunction, and vitamin A deficiency. Certain medications such as decongestants, hormonal therapies, and antihypertensives can also contribute.<br />3. Neurological impairment of the cornea – Due to contact lens use or refractive laser surgery.<br />4. Reduced blinking – Especially during prolonged use of smartphones, tablets, or computers.<br />5. Environmental factors – Exposure to wind, smoke, or dry air.<br />6. Lifestyle and health factors – Poor sleep, inadequate hydration, and unhealthy diet.<br /><br />Other contributing factors may also play a role depending on individual circumstances.<br /> <br />Conclusion<br /><br />Understanding the multifactorial causes of dry eye is essential for accurate diagnosis and effective management. Subsequent sections will cover the clinical manifestations and treatment strategies for dry eye.<br />