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Vision Process The vision process begins with rays of light from an object passing through the cornea. The image is then received by the lens, by way of the iris. Leaving the lens, the image falls on the rods and cones in the retina. The image then is carried to the brain for interpretation by the optic nerve (fig. 1-51). Note the image received by the retina is upside down, but the brain turns it right-side up. REFRACTION.-Deflection or bending of light rays results when light passes through substances of varying densities in the eye (cornea, aqueous humor, lens, and vitreous humor). The deflection of light in the eye is referred to as refraction. ACCOMMODATION.-Accommodation is the process by which the lens increases or decreases its curvature to refract light rays into focus on the fovea centralis. CONVERGENCE.-The movement of the globes toward the midline, causes a viewed object to come into focus on corresponding points of the two
Figure 1-49.-Anterior view of the eye. |
 
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