3. Dust
Dust is basically everywhere, and it can cause red eyes. Since most people see dust as something that is harmless, they don’t worry about it or even think it could be a reason for their eye problems. If dust particles get in your eye they can cause it to itch and even hurt. Dust particles easily move around and can contain germs and parasites. Any of these things can cause damage to your eye and make it appear red.
If you think you may have dust in your eye, you can try to flush it out with water or eye drops. In most cases, dust can work its way out on its own. If you have an allergy to dust mites, the redness can be worse, and you may have allergy symptoms as well. You can ask a doctor to test to see if you have a dust allergy, or for suggestions on treating ready eyes that you believe may be related to dust.