Fatigue maybe the cause, therefore try to rest them. Or Chalazion, which is inflammation of the eyelids. Use warm compresses on eye to reduce swelling. Yes, vision will be okay.
To reduce damage to the eye alternate between hot and cold compresses to reduce the swelling every four hours. Do not apply direct pressure to the eye.
flush your eye with water, take 200-800MG of Ibuprofen (Motrin) depending on Body size and relative pain if any, and put some ice on your eye for 20 minutes.
The best thing to do for the swelling if most likely a cool cloth to the eye. Do not use ice. You should try to determine why the eye is swollen such as a bug bite to determine what the proper action should be. Keep the eye free of discharge if there is any.
