Each 2.54 square centimetre (a square inch) of human skin has six metres (20ft) of blood vessels. Veins hold about 65 per cent of the body's blood and have one-way valves tohelp blood move.

The 'flexus (arm wing)' that grows on the surface of the eyeball in a wing shape is a disease in which fibrous blood vessels proliferate ... causing conjunctival erosion (hurt) on the eyeball ...