General Care Discussion :: Eyes closed - not swollen

[Tucker]

Lately my turtle has been sitting on the bottom of his tank with his eyes closed. They don't appear to be swollen, and when I approach his tank he opens his eyes and swims along the glass to greet me, but still continues to blink excessively, and when he blinks he keeps his eyes closed for 2-3 seconds before reopening them.
Sometimes when I check on him he is swimming normally or playing with his rocks or plants, but sometimes when I check on him his eyes are closed or he is blinking alot.
He other behaviours seen normal (eating, basking).
Suggested causes for closed swollen eyes include water quality (his water is always pretty clean but I did a complete filter cleaning and 30% water change a few days ago anyways to see if it would help and it didn't help his blinking) or vit A deficiency, but he eats fortified pellets and red leaf lettuce (he won't eat other veg or greens).
Could he just be really tired?
Has anyone else experience this with their turtles?

Basic Info:
How big is your turtle? 4-5 inch shell
How long have you had it? 1 year (he is 4 years old)

What is the water temperature? 77 F
Did you use a thermometer? yes
Are you using a water heater? yes
How much water is in there? 70 gallons
Are you using a water conditioner? nutrafin aqua plus
Are you using any filtration? fluval 404 canister filter

What is the basking temperature? 90 F
Is there a basking light? yes
Is there a basking platform that is easy to climb on? yes
What kind is it or what is it made out of? cork bark
Is there a UVB light? yes

What have you been trying to feed it? red leaf lettuce & nutrafin max turtle pellets
When was the last time your turtle ate? yesterday (he is fed every other day)

How big is the tank/pond/enclosure? 90 gallons
Is the tank near a window? yes but it is closed and draft free
Is the tank in a room with a lot of activity? no

Have you read the Basic Care section? yes
Have you searched the forums for similar situations? yes - all refer to eyes being swollen and his are not

Is there any other unusual activity/symptoms? no

Thank you for your help!

[steve]

If it's a problem with his environment, you can try to seek out the cause...
If you keep him out of the water for a few hours, does he still close his eyes often?
If you shut off the UVB, is there a change? Which UVB and basking lights are you using?

When did this start to happen?

[Tucker]

I don't normally take him out of the water - when he basks his eyes have been open when I checked on him.
I'm using a Repti Glo 10.0 26 W bulb and a Repti Glow ceramic heat emitting bulb.
He started the blinking/ eye closing about a week ago, and it seems like it's happening mostly in the late afternoons/evenings, which is why I was wondering if he is just tired? I am just concerned because it is definitely a change in his behaviour and I've never seen him close his eyes for any length of time during the day before this.

Have you heard/experienced this before?

[steve]

Do you think he's only blinking after a long basking session? If this is happening regularly, turn off the UVB and see if it continues.

[Tucker]

I haven't noticed a connection between basking sessions and the eyelids closing, I will watch for it.
To me it almost seems like he just wants to go to bed early, but with his light timers he already gets 12.5 hours of lights off a night. Although I know he doesn't sleep all night because I do usually hear him moving his rocks around at 3 am
Do you think he is napping? Do turtles even take naps?

[steve]

It's possible, but I haven't seen it happen very often.