<Li> Umbo - 0.15 mm (0.0059 in) </Li> <P> Structures in the macula are specialized for high - acuity vision . Within the macula are the fovea and foveola that both contain a high density of cones (photoreceptors with high acuity). </P> <P> Whereas loss of peripheral vision may go unnoticed for some time, damage to the macula will result in loss of central vision, which is usually immediately obvious . The progressive destruction of the macula is a disease known as macular degeneration and can sometimes lead to the creation of a macular hole . Macular holes are rarely caused by trauma, but if a severe blow is delivered it can burst the blood vessels going to the macula, destroying it . </P> <P> Visual input from the macula occupies a substantial portion of the brain's visual capacity . As a result, some forms of visual field loss that occur without involving the macula are termed macular sparing . (For example, visual field testing might demonstrate homonymous hemianopsia with macular sparing .) </P>

A progressive degeneration of the macula lutea of the retina is called