What are the causes and uses of the light refraction ?
The light refraction
The refraction of light occurs when the light passes across the boundary between two media , It is the change of light path when it travels from a transparent medium to another transparent medium of different optical density .
The transmission of light across a boundary between two media is accompanied by a change in both the speed and wavelength of the wave , and the light wave will not only change its direction at the boundary but it will change its speed and wavelength .
The ability of the transparent medium to refract the light is called the optical density of the medium , and it is the ability of the transparent medium to refract the light , and when the optical density of the medium increases , the speed of light through it decreases and vice versa .
The light will not refract when the light wave passes through the boundary in a perpendicular direction , And each medium has its own optical density , so , the optical density of a medium differs from one medium to another due to change in the light velocity through such medium .
Light refraction uses
The light refraction can be used in the clinical significance in medicine especially in the optometry , the ophthalmology and the orthoptics , the refraction is also known as the refractometry which is used to determine the eye’s refractive error and the best corrective lenses to be prescribed .
There are a series of test lenses in graded optical powers or focal lengths are presented to determine which provides the sharpest and the clearest vision , and the the cornea , the aqueous humor , the lens and the vitreous humor are refractive media .
The refraction of light occurs when the light passes from the air to the cornea in the eye , from the the cornea to the aqueous humor , from the aqueous humor to the lens and from the lens to the vitreous humor, and the light wave spreading out from one point on an object can therefore be focused on a particular point on the retina .
The images are formed in a camera by refraction in a manner similar to the image formation in the eye , So the accommodation to image closer objects is done differently in the eye and the camera .
The lens can focus the light , and it can produce converging or diverging light rays due to the refraction , and there are two types of lenses which are the convex lenses which cause the parallel light rays to converge , and the concave lenses which cause parallel light rays to diverge .
The convex lenses can allow the magnification , and the light reflecting off an object is focused to a point , and you should know that a magnifying glass is one the convex lens that allows the magnification of objects .
The microscope is basically a series of lenses that take the advantage of the nature of refraction of light due to the nature of light , The maximum amount of refraction that can be a possible by a material , there are limits to the amount of magnification that can be done by a light microscope .
Some media have an index of refraction that varies gradually with the position , So , the light rays curve through the medium rather than travelling in straight lines , So , the mirages can be seen on hot days where changing the index of refraction of the air causes the light rays to bend creating the appearance of specular reflections in the distance ( as if on the surface of a pool of water ) .