I have had an afterimage in my right eye for a month. I think it was caused by looking at a laser pointer type thing, but I don't think it was a real laser pointer. I think it was actually LED. I don't know why it's just the one eye or why it doesn't go away. Sometimes it seems like it is improving, but if I go out in the bright sunshine it gets worse again. I see it with my eye open and closed, but it fades after my eye is closed for a little while.
No discomfort, redness, or other symtpoms.