Dry eyes at night can be caused by various factors, including insufficient tear production, poor quality tears, or tears that evaporate too quickly. Below are some of the common causes of dry eyes at night:

• Nocturnal lagophthalmos: This is a condition where people sleep with their eyes open due to damaged or weakened eyelids.
• Dehydration: Not drinking enough fluids may reduce tear production or quality.
• Aging: Tear production tends to diminish with age.
• Certain medical conditions: Health conditions such as rheumatoid arthritis, diabetes, and thyroid issues can cause dry eyes.
• Certain medications: Some medications, such as antihistamines, decongestants, and antidepressants, can cause dry eyes while you sleep.

If you experience mild symptoms of dry eyes before or during sleep, it is usually not a cause for concern, and the symptoms should go away on their own. However, if your symptoms are severe, chronic, or do not respond to at-home care or over-the-counter treatments, you should talk with a doctor about dry eyes. Chronic dry eyes may lead to cornea damage or vision loss if not managed.

To prevent nighttime dry eyes, you can take some simple steps such as using a humidifier to add moisture to the air in your bedroom, applying a warm washcloth to your eyes, and avoiding prolonged contact lens use. If you wake up with dry eyes regularly, it is important to make an appointment with your eye doctor to determine the underlying cause and receive appropriate treatment.