In a classroom, while moving, the peripheral vision system, even with a dysfunctional oculomotor system, can at times signal the presence of objects or the location of doorways or landmarks. These kids have functional vision, they just can't control the eye muscles often enough to provide consistent, reliable vision. The cornea can be too steep or too flat. It can also deviate from a spherical curvature. An aspherical cornea causes two focuses and results in astigmatism.
Nourishment comes from the aqueous, and from a ring of blood vessels around the corneal rim.
If the cornea is cut seriously enough, blood vessels from the rim proliferate and grow into corneal tissue. These blood vessels remain even after the cut surface heals, leaving corneal scars. The iris is the colored part of the eye. It is a sphincter muscle, meaning that when it relaxes it opens, and when it contracts it closes. The hole in the iris that can enlarge or shrink, is called the pupil.