Final answer:
The percentage of humans born with a blind spot in their retinas is approximately 15%.
Step-by-step explanation:
The percentage of humans born with a blind spot in their retinas is approximately 15% (option b).
A blind spot in the retina, also known as the optic disc, is a natural feature of the human eye. It is the area where the optic nerve exits the eye, and it does not contain any photoreceptor cells, such as rods and cones, which are responsible for vision. Therefore, this area lacks the ability to detect light, resulting in a blind spot in our visual field.
Based on statistical studies, it has been estimated that around 15% of humans have this blind spot in their retinas.