Thus, sight just is that power by which we are aware of the colors of material things.
What one means by an external sense is obvious: one of the five means by which we are directly aware of the world around us. They are sight, hearing, smell, taste and touch.
A persons biological because its the only one that makes sense according to the study of genetics. EX: X chromosome are always in females eggs, while the x & y chromosome is in the male.
