Dat lost sight but not visibly blind ?!

[pupumole]

Hmmm...

Strange thing happened this week. My 15" dat seems to have gone blind but there are absolutely no sign of damage on the eyeball. Could ammonia have caused some nerve to be damage so it lost its eyesight? It looks completely normal except when we drop food in front of it, it can't see it , and can only eat if food actually hit its mouth. Another dat was fighting with him and scratched him up just a little, could it get infected somehow and lost its sight? Any idea what's going on?

 

[addisonlee25]

Maybe cataracts?? Interested myself..

 

[yh_loh]

maybe due to quality of the water.... I have experienced my NTT turn almost blind but when quckily transfer him to outside tank which expose to rain and thunder,
it turn back to normal again. The best quality of water for fishes is to expose to sun, rain and thunder because with rain and thunder it will neutralise the water condition. I never do water change almost few years of my tank outside my house but the water is still very clear and the fish inside the tank is super heathy and growing very fast.

 

[pupumole]

i've had a widebar that had cataract shift, but it doesn't seem to be the case on this one...
I'm thinking more of quality of the water since there were some amount of ammonia in there when i tested it couple days ago. I wonder if it is permanently blind or not though. hope not