General Care Discussion :: Is his blinking normal?

[Summer]

Hello everyone! It has been a while since my last post. Luke, my RES, has been quite healthy -- sleeping, eating, basking in the morning sunlight, and shedding his brains out.

But his blinking... It worries me a little because I see absolutely nothing wrong with his eyes, and yet Luke often blinks as if he is winking. By this, I mean that he blinks with one eye at a time. He doesn't do it 24/7, but when I approach him to play or say hi, that is how he blinks. Is this normal for RES, or turtles in general?

I have linked a recent photo of him below and did my best to capture both of his eyes. I wonder if when he flutters (normally right against the glass), does he possibly hurt/scratch his eyes with his nails?

His tank water is cleaned regularly (every 3-5 days) and there is a filter present.

Thanks in advance for any advice!

http://i1381.photobucket.com/albums/ah226/K-Summer/Mobile%20Uploads/IMG_20160812_231545_zpss8ucjjfo.jpg

[steve]

I do see it happening sometimes with my RES, especially when out of water (or the head just poking out).

[Summer]

I'll assume that Luke's blinking is normal then. He's been doing it for over year, from what I can remember, and I've never seen any indication of infection/injury.

He does it in both water and out of water... I think I'll pay more attention to whether or not he does it in water after exposing his eyes out of water.

Thank you!

[steve]

Is he alternating it or is it always the same eye?