Presbyopia is the visual in
which there is of the cililary muscle
thus reducing the capability
the crystalline lens to of
near objects onto retina. In
presbyopia the point of vision
becomes distant. The disease
generally in old people.
Astigmatism caused by irregular
shape the refractive structures,
mainly cornea. In astigmatisma
single -point may produce more
than image onto the retina so
the vision becomes .