Most often, if your rabbit has watery eyes, and no other worrying symptoms, they are experiencing allergies. Try changing bedding, food, and if possible the room they are kept in.
It might be sick. You might want to go to the vet and get it a checkup. Or was it like that since you bought it? It might just look like it has watery eyes. Either way I'd get it to the vet. Just to make sure it isn't sick.
There are a lot of reasons for this phenomenon, with the most common reason being that your rabbit has allergies. For this reason, it is important to always clean out the rabbit's cage regularly.
There are lots of breeders that believe all rabbits carry diseases, although there is one disease that causes watery eyes, it is call Pasteurella. You can take your rabbit to a vet and determine if this is the cause. Usually a treatment of antibodics will clear it right up and they will be back to normal.
