Why have people advised to wash their eyes with plenty of water
Answers
I do not think it is OK to wash your eyes out with tap water except in an emergency situation where you got a damaging chemical in the eyes accidentally and need to irrigate it out. There is less salt in tap water than in normal human tissue and tears. This can be very irritating to the ocular surface and even cause damage to the surface cells. Also, using tap water or homemade saline to rinse contact lenses has been associated with severe ocular infections with multiple pathogens including acanthamoeba. If you felt the need to irrigate your eyes in a non-emergent setting, then a commercially prepared eyewash made for the ocular surface is much safer than tap water.
Explanation:
The idea behind washing eyes with water appears to be to clean the eyes and remove dust/dirt, feel fresh and cool in hot weather etc