Oh, I think all foreign stuff getting into the eyes will make the eye uncomfortable.The sperms in your eyes will irritate your eyes. It will make your eyes sting or turn red, itching. Please do not worry about it too much. If you happen to get it into your eye, please use the tap water rinse your eyes repeatedly until you feel better.
Yes, it is bad to eyes when you get the sperm in the eyes. There are many side effects of eyes. Your eyes will get red because of stimulation. Your eyes will become uncomfortable and you may have the feeling to get watery. You'd better wash the eyes clearly with clean water. Then you could do the warm compress to make your eyes get comfortable.
Well, yes, sperm in your eyes will just affect your eyes, leading to further eye problems. According to some researches, sperm in your eyes will lead to eye infection in some cases. Because of that, your eyes will just feel red, and itchy. At this time, of course, cold compresses with some cool tea bags can be very effective. Also, some eye drops can be applied too.
Well, our eyes are too sensitive to stand any foreign stuffs, although sperm cells have a very limited life span. Besides, the seminal plasma that contains sperm is a nutritive and protective medium. Further, as the normal environment of the vagina is very acidic, which is hostile for sperm cells, some alkaline bases like putrescine or cadaverine are included in the seminal plasma in order to compensate to this hostile environment. So such stuffs will hurt our eyes by changing the PH level. What you need to do now is to rinse your eyes with saline solution.