I noticed this after changing his water, one of his eyes has a slight pink tint to it on the upper eye lid. It doesn't look inflammated and has no problem opening and closing his eyes. He doesn't scratch at it or anything. I only noticed it under direct light and up close. I wonder if he somehow hurt himself against a rock or the basking platform by head butting it since it sits above the tank and the ramp sticks out in the water. Or is this the start of an infection or vitamin deficiency? Or is this normal?