Which structure is referred to as the 'white part' of the eye?

The sclera is commonly referred to as the 'white part' of the eye because it is the tough, opaque outer layer that surrounds and protects the inner components of the eye. The sclera maintains the shape of the eyeball and provides an attachment point for the extraocular muscles, which control eye movement. Its white appearance is due to the presence of collagen fibers and is an essential part of the eye's structure.

The cornea, while also part of the eye, is transparent and located at the front, making it responsible for refracting light but does not have the white coloration characteristic of the sclera. The iris is the colored part of the eye responsible for controlling the size of the pupil and the amount of light entering the eye, while the retina is the light-sensitive layer at the back of the eye that detects light and sends visual signals to the brain. Each of these structures serves a unique function, but only the sclera is identified as the 'white part' of the eye.