The part of the image projected on the fovea is usually the most accurately registered visual memory. The center of macula is called fovea, which contains the highest concentration of cone cells.
Retinal membrane contains an area called macula, which is yellow in color. Deficiency of either type of cells would cause abnormalities in the ocular function. Cones play a critical role in perception of the images with sharp contrast. The former are considered to be responsible for dim light vision, whereas the latter are considered to be responsible for bright light vision. In addition to tissue components, retina is made up of two types of cells: rod cells and cone cells. The light passing through cornea, pupil, and lens gets focused on the retinal membrane. Retinal membrane can be imagined as the wall on which the images are projected. Retina is the innermost layer of the eyeball structure. It refracts the light, and helps in focusing it correctly to the back of the eyeball (retina). The lens is encapsulated in a thin transparent body, and is connected with the eyeball by a pair of muscles. It is flexible in nature, and adjusts according to the external lighting. Located right behind the pupil is the transparent structure termed as the lens, responsible for correct focusing of the visuals. This is the reason we can’t see anything for few moments when we enter from bright sunlight to a dark interior, and also the reason we can’t keep our eyes wide open when we suddenly switch on the lights in the middle of the night. The process of dilatation and constriction of pupil is not instantaneous. In bright environments, the pupil of the eye constricts, while in dark environments, it dilates. Just like the aperture of a camera, it controls the amount of light that goes in. It is circular in shape, and allows light to pass through onto the lens. The central aperture of iris is called pupil. Eye color (black, brown, blue etc.) is defined by the pigmentation of iris. The central portion of the front of the eyeball is termed as iris. Its function is of a primary filter, before passing on the light to the lens and retina.
Cornea is the first optical component of the eye machinery, dealing first-hand with the incoming light. Boundaries of eyelids are covered by tiny hairline termed as eyelashes.Īs we go past eyelids, the next component is the circular frontage of the spherical eyeball, termed as cornea. They act as ‘shutters’ and primary barriers against external environment. This biological camera is made up of: External ComponentsĮyelids are the outermost protective parts of the eye. The entire machinery works in quite an intricate manner. Optical components create an image, which further gets perceived and interpreted by the brain via connecting neurons. Humans have binocular vision, meaning that both the eyes create a single combined image. A healthy pair of eyes means a clear vision, which plays a major role in day-to-day life and quality of experiences.
Reviewed by Susha Cheriyedath, M.Sc.Įyes are one of the most important organs of the body.
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