Question

What is a yellow spot?

Answer 1

Hint: Yellow spot is present in the human eye. It is the very important centre in the eye. It is present in the retina. Another name of the yellow spot is the macula.

Complete answer:
The eye is an important sense organ for vision in human beings. The eye consists of a lens that focuses the image on the retina. The retina is the cellular layer on the eye which receives the signals and send them to the brain. The point at which the image is formed at the retina is known as macula or yellow spot.

The yellow spot is present at the centre of the eye on the retina. It is oval in shape with a size of about 1.5mm. It is the area of maximum sharpness in the eye which is responsible for making us see clearly. This spot is yellow in colour which absorbs blue and ultraviolet light. This spot has the maximum amount of pigments called zeaxanthin and lutein due to which it appears yellow. It contains the maximum concentration of cone cells.

It is subdivided into areas like umbo, foveola, fovea, parafovea, perifovea and foveal avascular zone. The damage of the macula results in the impairment of the vision. Macular degeneration can result in loss of central vision.

The yellow spot is shown with the help of the diagram below-

Note: The eye has another region called the blind spot. It is the region where the optic nerves leave the eyeball. This region does not contain any photosensitive cells like rods and cones. Thus this area is the region of no vision. It helps in the transmission of impulses to the brain.