A regular bulb does not get hot enough to heat a BP enclosure to the temps it needs to be. BP's are extremely sensitive to temps. You have no thermometer or hydrometer to even see what its temps are. (And they are guaranteed crappy because you don't use a real heat source. And I know this because you also don't even mention having the most basic thing; an under tank heater.) You do not have reptile vets where you live. Most animals need a vet visit at least once in its entire life and for something that can live to be 20 years old, definitely more than 3.

This can possibly be a burn from the bulb, which since you don't even meet basic care requirements, I wouldn't be surprised you put IN the enclosure, exposed, without even a wire cage around it to keep the snake from direct contact of it. BPs climb sometimes. The problem with its eye, since temps are very likely wrong, is that it may have a retained eye cap (which you even called a cap) that may be squeezing the poor thing's eye and causing very light bleeding.

There isn't a lot a forum board can tell you, except hearsay. You need a vet. Need one. Period. Even if we correctly guess what is wrong, it still needs proper official diagnosing, and medication from a verified vet.And that's not a "if we're right" scenario. That's as it is, right now, where this snake's health currently is.

If you don't have vets for this type of animal, then don't get this type of animal.