My Rabbit Has Fur Loss Under It's Eye?

I have 2 rabbits who are both 3 years old and then are adults. They are white with bits of grey fur on them and they are very healthy. They get cleaned out once a week and usually get a run every day and we've never forgotten to feed them. They have both been neutered. One of them had an eye infection last summer and the vets gave us some eye cream for him and some antibiotics for him (which we used and he got better). But just this afternoon I was cleaning them out and I realised the rabbit who has had an eye infection before, which is gone now had some red under his eye. I had a closer look and I realised it was skin and there was no fur under his left eye. Is this bad? Does he need to go to the vets? Do you know why he has no fur under his eye? Please comment I don't want my rabbit to be ill. ThankYou xx