Mathematics. 1  Also called relative maximum, local maximum. the value of a function at a certain point in its domain, which is greater than or equal to the values at all other points in the immediate vicinity of the point. 2  the point in the domain at which a maximum occurs.
For other uses, see Blindness (disambiguation). Visual impairment, also known as vision impairment or vision loss, is a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses. Some also include those who have a decreased ability to see because they do not have access to glasses or contact lenses.
Cortical visual impairment (CVI) is a decreased visual response due to a neurological problem affecting the visual part of the brain. Typically, a child with CVI has a normal eye exam or has an eye condition that cannot account for the abnormal visual behavior.