IT looks like he has pop eye. For this you want to keep him in clean water, and use epsom salt. I would suggest getting a small quarantine tank to keep him in during treatment, or if you can get a small container to float in the 10 gallon to maintain warmth.
I suggest you premix the treatment water, in a seperate container, use 1 tsp of plain, undyed, unscented epsom salt (you find this in the pharmacy section of a store) and water conditioner/dechlorinator. IF you have any IAL or oak leaves (dried and pesticide free) you can add this as well.
Make sure you stop the AQ salt, this will only make it worse. You want to do daily 100% water changes in the QT tank.