There are several eye infections caused by bacteria and fungi that can turn the cornea opaque. In addition the eye can be traumatised by pond conditions and injuries. Such infections are often referred to as cloudy eye as though it was one single disease which is not the case.
Clear Eye Lotion can help with some infections. In mild cases a drop of Clear Eye Lotion can be dripped onto the eye directly but in severe cases a cotton wool ball or cotton bud soaked in the lotion should be gently used to bathe the cornea. This can be repeated as often as the fish tolerates handling but at least twice per week. Use a clean cotton wool ball or pad for each eye and treat both eyes at the first treatment even if only one appears affected.
In addition, When working close to the eye, we usually coat the eye with ‘clear eye’ to protect it from any adjacent stray coatings.