Cory With Swollen Eye

Hi,

i can't be sure from the pic, but it looks like pop-eye. This is fluid in or behind the eye and may eventually lead to the loss of the eye. If it was both eyes then i would say it was a bacterial infection. As it seems to be one eye it may be from trauma, eg fightlng or banged the eye.

If your spare tank was available i would suggest using Epsom Salts. It has been used with good results by people in the past to draw the fluid out. One tablespoon per 5 gallons of water for at least three days, longer if necessary. Epsom salts isn't really salt (sodium chloride) it is Magnesium Sulfate. 

Search the web for pop-eye, there's loads of info out there, see if it does ring true to your cory's condition.

Here's hoping all goes well.