"Sounds strange but the outside characteristics of a lions face enhance their night vision. The white strips under their eyes reflect faint light into the eyes, maximising the amount of light entering the eye. This characteristic is a good indication that this animal is nocturnal, if you look at cheetah eyes the opposite is true. Cheetah have black tear marks reducing the glare, while they are hunting in the daylight hours. Much like the way an American Footballer puts black face paint under their eyes."