do NOT give the gar melafix for cloudy eye...it's best not to use melafix or pimafix with gars in general.
cloudy eye can develop in gars for several reasons, but if your water parameters are good, then don't worry about it unless the cloudy eye becomes much worse. i've had gars fluctuate with this condition quite a bit over the years, and other than the cloudiness in the eyes, they don't seem any worse for wear. this is different than in many other fishes where the cloudy eye usually indicates an underlying and often more serious issue.
just keep up with the water changes and monitor your parameters and your fish will be fine. at this time i would not be concerned with the condition unless it continues to get worse. keep us posted--
--solomon