The ouch: Dryness
Hot and windy environments can evaporate the moisture on your eyes, says Rachel Bishop, M.D., chief of consult services at the National Eye Institute. For some particularly contact lens wearers, a week at the beach could initiate dry eye. Nix it by using lubricant drops during and after beach days. If those don't help, you may need a doctor to prescribe an anti-inflammatory.
The ouch: Irritation
The good news is that ocean water itself isn't dangerous to eyes, but if you're swimming in a crowded spot, use goggles to protect against lurking pollutants. Ditto for contact lens wearers, even in pools. On land, gritty sand, shell fragments, and dirt abound. If a particle gets in your eye, rinse it with fresh water so it doesn't scratch your cornea. See an eye doctor if it still bothers you a day or two later.
The ouch: Sunburn
Extended time in front of the sun even three hours could burn the surface cells of your cornea, which is painful and can cause partial or full vision loss (usually temporary, but not worth finding out). Always wear shades whose label touts either 100 percent UV protection or UV 400 they mean the same thing, ideally tight fitting ones that extend well past the outer corners of your eyes, as these prevent rays from sneaking in. Visit a doctor immediately if your eyes are red, swollen, or stinging.