Definition of blind spot

The term "blind spot" refers to an area in our visual field that we cannot see without moving our eyes. This phenomenon is due to the anatomy of our eyes and the way our brain processes visual information. The retina, the light-sensitive tissue at the back of our eyes, is not uniformly covered by photoreceptor cells. Rather, it contains a small region called the blind spot, which is roughly the size of your thumb at an arm's length when your eyes are open. This area has no cones or rods, the two types of cells that convert light into electrical signals for our brains to interpret. When light enters our eyes and falls on the blind spot, it is not detected by our photoreceptor cells. Our brain compensates for this by filling in the missing information using data from neighboring areas of the retina. This is known as perceptual filling-in, a process that allows us to see a continuous image even when some parts of it are not directly perceived. The discovery of the blind spot was first reported by the German ophthalmologist Hermann von Helmholtz in the mid-19th century. Today, it is a familiar concept in psychology, optometry, and vision science, and has been used as a metaphor in various contexts, from describing blind spots in decision-making to highlighting the limitations of personal perspectives.