What Causes Dry Eyes? 8 Surprising Triggers Most People Miss

The short version

Dry eye comes down to two problems: not enough tears, or tears that evaporate too fast. Most patients have a mix of both. Here are the triggers we see most often, including a few that surprise people.

1. Screen time

When you stare at a screen, your blink rate drops by more than half according to research. The blinks you do take are often incomplete. Fewer blinks means your tear film isn't being refreshed, so it doesn't replenish as often as it should.

2. Medications

Antihistamines, antidepressants, blood pressure medications, acne treatments, and some birth control pills can all reduce tear production. Never stop a medication on your own, but do tell your eye doctor everything you take.

3. Contact lenses

Lenses sit directly on the tear film and can disrupt it, especially with long wear hours or sleeping in lenses. Also old overused lenses cause extra friction with the inside of the eyelid every time you blink. This over the course of years will wear out your meibomian glands that produce oil to keep your tears healthy. This leads to evaporative dry eye over time. Discuss new lens options with your Dr.

4. Allergies

Allergy season inflames the eye's surface, and the antihistamines used to treat allergies dry it out further due to the anti-cholinergic affects of the medication. A frustrating double hit that's very common here in Ventura County.

5. The quieter culprits

• Hormonal changes- Especially during pregnancy, menopause, or with thyroid conditions. Hyperthyroid can be diagnosed with a comprehensive in office eye exam depending on the stage.
• Eyelid oil gland blockage (MGD)- The most common cause of evaporative dry eye, and it often goes undiagnosed. This needs proper equipment such as a meibographer to diagnose. 
• Environment- Wind, coastal air, air conditioning, and indoor heating all accelerate evaporation artificially.
• Age and health conditions- Tear production naturally declines after 50, and conditions like diabetes, rosacea, and autoimmune disease raise the risk.

When to see an optometrist

Because so many different things cause the same symptoms, guessing rarely works. A comprehensive eye exam should be scheduled every 2 years regardless of good vision. This is more for ocular health and we take your eye health serious at our office. A dry eye exam lets us identify your specific triggers and treat the actual cause which is why our patients get relief when years of drugstore drops didn't help.