The function of the macula lutea is to provide accurate and detailed central vision. It gets its name because it's a yellow spot in the macula, which is in the center of the retina. It is abundant in specialized light-sensitive cells called cones.
The macula lutea is about 5.5 millimeters in diameter, and its yellow color is the result of the carotenoids lutein and zeaxanthin. These pigments absorb the ultraviolet light that falls into the eye and protect it somewhat from damage. These carotenoids are mostly found in the Henle fiber layer.
The regions of the macula lutea include the fovea, the foveal avascular zone, or FAZ, the foveola and the umbo. The fovea and foveola are especially rich in cones. The optic nerve transmits about half of its information from the fovea to the brain, while the other messages are transmitted from the retina in general. The foveola is a tiny area in the center of the fovea and has the greatest density of cones.
Damage to the macula lutea will impair central vision, which makes it extremely difficult to perform detailed tasks such as reading or sewing. A condition known as macular degeneration is common, especially as a person ages.