What structure of the eye is commonly referred to as the "blind spot"?

The structure of the eye commonly referred to as the "blind spot" is the optic disc. This area is located where the optic nerve leaves the eye, and it lacks photoreceptors (rods and cones), which are necessary for detecting light and forming visual images. Because of this absence of photoreceptors, any image that falls on this part of the retina cannot be perceived, creating a "blind spot" in the visual field.

In contrast, the cornea is the transparent front part of the eye that covers the iris and pupil, playing a key role in focusing light. The iris is the colored part of the eye that controls the size of the pupil and, therefore, the amount of light that enters the eye. The pupil itself is the opening in the center of the iris through which light travels into the interior of the eye. None of these structures create a blind spot in the way the optic disc does, as they all contain photoreceptors or are involved in processing visual information.