How the Eye Converts Visible Light to Neural Activity - Essay Example

The eye’s first adaptation to its interaction with light is referred to as the pupillary light reflex. When responding to different levels of light, the rods and cons work independently but back up each other. This modus operandi espouses the eye’s adaptation to dark light. While the rods are sensitive to light, they have the tendency to take a significant amount of time to adapt to darkness, in this case, the rhodopsin, situated in the photoreceptors take full charge through photobleaching.

On the other hand, the regulation of the eye’s sensitivity eye’s to light is espoused by the changes in the intracellular calcium ions. In order to adapt to light, the eye first adapts to the background so that it is capable of detecting and distinguishing the background objects; the entire process of adaption to light takes a period of approximately five minutes Whenever light is reflected on a surface or remitted from an object, the eye detects the light that first encounters the cornea; from here, it is then focussed to the lens.

The lens in turn functions to vary the focus depending on the distance that exists between the eye and the object. The focal adjustment of the light by the lens is called accommodation. The lens alters its shape depending on the distance of the object; for objects that are distant, it elongates, flattens, and pulls out whereas, for objects that are close by, it only needs to assume its natural round shape for clear vision. The light first passes through the space between the cornea and the lens that is filled with fluid called aqueous humor.

It consequently goes through the t pupil‘s circular aperture that is surrounded by the iris diaphragm muscles prior to going through the lens (Jones, et al 2004). However, the quantity of light that passes through the pupil is determined by the pupil’s diameter and still goes ahead to be regulated by the iris’s circular and radial smooth muscle fibers. This regulation is controlled by the autonomic nervous system. The aperture’s diameter decreases with the contraction of the circular muscle and enlarges with the contraction of these muscles. The real image of the object that can be seen at that time is consequently projected to the retina whose location is at the back of the eye.