A human eye and a camera have many similarities. The Boston University Physics website explains that the eye's pupil and retina are similar to the shutter and film of a camera. The pupil and shutter regulate light and the film and retina record images. The lens focuses light and creates an image in both the eye and the camera. The website notes that the human eye adjusts focus automatically but the camera lens must be adjust to focus images at different distances.
Lens and Shutter
According to library.thinkquest.org, the camera draws in light through the lens; the light then bounces off a mirror and travels through a prism. The prism reflects the lighted image to the back of the camera where it enters light-sensitive storage cells or film. The eye draws light through a lens behind the cornea. The pupil then focuses this light, notes the Jules Stein Eye Institute, at jeis.org. Lens and shutters allow light to enter both the eye and the camera. The camera lens must adapt the focal point of images such as normal, wide angle and telephoto, notes the website, library.thinkquest.org. The camera also requires a mirror and a prism to refract reflected light and project that light at angles to the back of the camera.
Pupil and Shutter
Although the pupil regulates light that enters the eye, the shutter can allow too much light into the camera and must be monitored or manually adjusted. The healthy eye is able to regulate the type and intensity of light entering the pupil. The camera uses the diaphragm to adjust more or less light to create a similar image with flash settings. The camera diaphragm works similar to the pupil, adjusting light frequency entering the aperture, notes library.thinkquest.org.
Retina and Film
The retina of the eye transfers images in electrical impulses to the macula that processes detailed vision, according to the Jules Stein Eye Institute. The optic nerve then transfers these signals to rods and cones that store the impulses on the way to the brain. Once the brain receives these electrical stimuli, it recreates an image. The camera requires a mirror and a prism to refract reflected light projected at angles to the back of the camera. The refracted, electrical impulses are stored on film or within storage cells for digital cameras.
Major Differences
The major differences between the healthy human eye with 20/20 vision and the camera are the speed at which the eye completes similar tasks and adjusts for distance, light and movement. The camera requires added hardware such as adapted lenses, diaphragms, flash, speed shutters and in some instances film to recreate the perfect image projection of the human eye. However, a damaged camera can replace this adapted hardware but a damaged human eye is more difficult to repair, such is the case with a damaged macula, retina or optic nerve.
Technology Narrowing the Differences
The National Science Foundation notes that new technology studied in 2008 could create a camera with a greater similarity to the human eye. This technology will allow cameras to improve images through a wider field of vision. Northwestern University and University of Illinois researchers, states the foundation website, have evaluated a way to move electrical impulses from a flat surface in current technology to a curved surface similar to the lens of the human eye. The curved surface will act as the focal point of a camera, developing a view based on a greater array of light moving through and around a curved surface.
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