I have a female molly who has developed one white eye - its completely white and not bulging or anything. Her behaviour and feeding is normal.
Any views?
I agree its mostly "cloudy eye", a condition either brought on by water quality problems/irretants in the water, or bacterial infections or other stressful causes- as wilder said, you should test your water for ammonia, nitrites and nitrates as water quality issues are the most common cause for sickness in fish .