There are a few options. Most likely are a bit of fuzz/mucus on the eye (if it looks like it's on the eye and you can pick it off gently), a corneal ulcer (basically a scratch on the eye, can get infected and cause real issues), a deposit in the eye (usually from E cuniculi), or congenital glaucoma/cataracts. I would have the vet take a look at it because if it is a corneal ulcer, and it goes untreated, it can go very badly. We had a bunny come in to the shelter a while ago who had been surrendered to the Humane Society at the emergency vet clinic. The eye had had a white spot on it since the owner had bought the bunny, and she never thought anything of it, until one day the eye ruptured and she had to take him to the emergency vet. She couldn't afford the required surgery (to remove what was left of the eye), so she surrendered him to the Humane Society and the clinic did the surgery and handed him over to us. It was a very sad situation and I know the bunny suffered a lot and the owner just didn't know what was going on, she probably suffered quite a bit of emotional trauma from the experience too. The bunny got a new home easily, even with one eye, but it's a story I like to remember whenever there's what appears to be a small problem with an eye. They can get out of hand very quickly.
The vet has a special dye they can put in the eye and look at under a certain light to look for a corneal ulcer. If it is not that, they can usually tell if it is a EC-related deposit (usually a fat or keratin deposit, will have more defined edges and a non-symmetric shape), cataracts, or glaucoma. Cataracts and glaucoma have more diffuse edges to the spot and are usually circular and symmetric. Glaucoma usually leads to the eyes bulging a bit too due to intra-ocular pressure.
At that age, it's certainly not one of the age-related diseases, but glaucoma and cataracts can be genetic. I would think it is most likely to be EC-related. That does not mean that the baby needs to be PTS, or will suffer horribly throughout its life. It may never develop other signs of EC; but it may progress rapidly through the disease. I have seen bunnies with things like this in their eyes at the shelter that are fine and seem to stay fine. On the other hand, SnowyShiloh's Rory developed this and died from EC within less than a year. It's hard to tell.
If it is EC-related, I would say that he does have a greater chance of developing a life-threatening active EC infection than a bunny without the spot. However, all bunnies have been exposed to EC at some point in their lifetimes, so they have a chance of getting it too. It just will mean that you will need to keep a closer eye out for other signs of an active EC infection in him as he ages, like hind leg weakness, urinary issues, head tilt, movement problems. It also might be good to treat him with an antiparasitic (preferably Marquis/ponazuril) and his littermates and mom the same (or, if cost is prohibitive, fenbendazole/Panacur).
Most bunnies are exposed to EC through the urine of other rabbits housed near them while they are growing up. The presence of white spots in the eyes of a very young bunny means that it was exposed to EC in utero, as the parasite can cross the placenta from the mom. That's why you'll want to keep a close eye on him, his littermates, and his mom IF it turns out to be an EC-related deposit.
