![]() ![]() ![]() Then, the light arrives at the eye’s lens, where it is collected and transferred to the photosensitive (=light-sensitive) retina. Next, they pass through the anterior chamber and the pupil. If we look at a tree, our eyes absorb the light it reflects: the rays first penetrate the conjunctiva and the cornea. This light is then reflected back by the object and processed by our visual apparatus. Specifically, this means that if we are to even have a chance of seeing an object, some light has to fall on it. In complete darkness, we are virtually blind. Then, each eye forwards this image to the brain via the optic nerve and processes it, resulting in what we call “vision.” Light forms the basis of everything we see. This results in an initial visual impression. Put simply, vision happens like so: the human eye absorbs light from its surroundings and collects it on the cornea. We talk about the retino-cortical pathway, which begins at the eye and runs all the way to our brain. It supports retina and refracts light to focus on retina.The way we see things is all part of a complex process: before we see something, a string of individual steps occur in the eye and the brain.It is filled with gelatinous vitreous humour containing salts and muco proteins.It is a larger fluid filled chamber between lens and retina.The aqueous humour nourishes the lens and cornea and refracts light rays to focus on retina.It is filled with aqueous humour containing aminoacids, glucose, ascorbic acid, hyaluronic acid and respiratory gases.It is a smaller fluid filled chamber between cornea and lens.Lens separates the eye ball into two chamber.It forms the image of the object on retina.Ciliary muscles control the thickness of lens and its power of accommodation.Lens is enclosed in a transparent elastic capsule.It is a large, flexible, transparent biconvex and fibrous crystalline body situated behind iris.Contains a photosensitive pigment iodopsin.It functions in bright light and differentiate colors.Cones are sensors for perception of colors.It is least sensitive to light and forms no image when light falls on blind spot It does not contains any rods or cone cells. The optic nerve enter retina at a point called blind spot.Fovea centralis is highly sensitive to light and forms magnified image and give sharp and acute vision.Small depression in retinal wall is called Fovea centralis which contains only cone cells.Each eye ball has 125 millions of rod cells and 7 millions of cone cells.Neuroretina contains highly specialized photoreceptor nerve cells rods and cones.It consists of photoreceptor cells and photo sensitive elements. Iris control the amount of light entering into eye by controlling the size of pupil.The movement of these muscles control the size of pupil. ![]()
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