Whats this on my bn pleco?

[Goldfish loach boy]

I got this pleco this weekend, and there is this white thing over it's eye, and that eye Is also bigger than the other one what is this help?!!

 

[Scottyhorse]

Can plecos get hole in the head disease? From what I've heard it's more of a cichlid thing, but you might want to look into that.

 

[Goldfish loach boy]

Hole in the head, I'll research that, nothing else unusual, very active, just that thing, it worries me