White rings around base of bettas eyes

[GobyMaster11276]

So, if having to take a cat to the vet in the middle of the night wasn't bad enough, this morning I noticed a white ring around each of Percy's eyes. They are very small, and there has been not appetite or behaviour change in Percy. What could it be? I tried to get photos but it's a bit difficult (because he doesn't like to stay still while I'm watching him). Let me know if you can't see the images properly.

The water parameters are being tested now. The tank is 35l on Percy's side, planted, and about 26-26.5 degrees Celsius in the water. Thanks in advance.

 

[GobyMaster11276]

The parameters (forgot to put them up earlier) are:
pH: ~7.8
Ammonia: 0-0.25ppm
Nitrites: 0ppm
Nitrates: 10-20ppm
I will conduct a water change now. Any advice or help is greatly appreciated. Thanks.

 

[NickAu]

I cant see anything wrong in the photo but then my eyes are not the best. Im not saying that there is nothing wrong just that I cant see it,

 

[GobyMaster11276]

I cant see anything wrong in the photo but then my eyes are not the best. Im not saying that there is nothing wrong just that I cant see it,

It's a bit hard to see in those photos actually. I think the best is fourth, in which just above the eye you can see it.

 

[LyraGuppi]

They look normal to me. Have they had any sort of swelling?

 

[GobyMaster11276]

Nope, no swelling, or anything else.