The part of the human body that has no blood supply is the cornea of the eye. Unlike other tissues, the cornea does not contain blood vessels. Instead, it receives oxygen and nutrients directly from the tear fluid on the outside and the aqueous humor (the watery fluid between the lens and the cornea) on the inside. This unique arrangement allows the cornea to remain transparent, which is essential for its role in directing light into the eye. Other body parts without blood vessels include hair, nails, tooth enamel, and the outer layers of skin, but the cornea is the only living tissue that completely lacks blood supply. The absence of blood vessels in the cornea is also why contact lenses can affect oxygen supply, sometimes causing blood vessel growth into the cornea as a complication.