I have a mithrax crab and hes normally really scared of people getting close to the tank or lights turning on. I took a picture of the tank at night using flash and I think he may have gotten blinded by the flash. This morning when the lights came on, he was just sitting on top of a rock as if he couldnt tell. (normally he scurries away as soon as there is light) Could he be BLIND?! Will that affect his algae eating capabilities?