Narrow eyes are a common physical feature that can be used to distinguish one person from another. But who would have thought, it turns out slanted eyes or small greedy could be one indicator of the possibility of certain diseases or medical conditions. The shape of a person's eyes is determined by the upper and lower eyelids. The angle of the eye close to the nose can be covered by the skin of the upper eyelid. This skin that closes is called the epicanth fold. This fold makes the eyes look more narrow. This is normal in people of Asian descent. Various Causes of Narrow Eyes However, in some cases, slanted eyes can be an indication of certain medical conditions. The following are some conditions or diseases that can cause slanted eyes: Down syndrome Down's syndrome is a genetic disorder characterized by physical abnormalities and delayed body growth. Narrow eyes, small mouth with protruding tongue, flat back of the head, only one stroke on the palm of the hand, and