An image is formed in the human eye when light passes through the pupil, is refracted by the lens and is absorbed by pigment cells in the retina, altering the pigments and triggering neurons to fire. The particular arrangement of the stimulated cells is interpreted by the brain into a separate image for each eye. The two eyes look at images from slightly different angles, allowing the perception of depth.Know More
The human eye is a complex organ capable of perceiving relatively great detail. While other organisms have better vision in low-light conditions or at great distances, the combination of precise color perception, depth perception and general acuity at close distances is very strong in humans. The eyes are capable of adapting to varying distance and light levels.
When light passes through the lens, it is inverted, so light that hits the top of the retina comes from the bottom of the field of view and the light on the left of the retina comes from the right part of the field of view. The brain automatically reorients this information to its proper location. The retina has two different types of sensors, rods and cones, which are responsible for low-light vision and color vision, respectively.Learn more about Vision
According to the Eye Care Office of Ofner, Neale and Fleming, cataracts of the eye create a clouding of the lens inside the eye, behind the pupil or iris (the colored portion of the eye), that is often mistaken for a film over the eye. Cataracts are a common aspect to the aging process. Early signs of cataracts include decreased distance vision and decreased vision while reading.Full Answer >
The amount of light entering the human eye is regulated by the diameter of the pupil. The pupil is the dark spot at the center of a healthy iris that, according to the National Institutes of Health, rests immediately in front of the eye's lens.Full Answer >
Eye floaters and flashes can be the result of the retina becoming detached from the inner back of the eye or the vitreous pulling away from the retina, says Marilyn Haddrill of All About Vision. Ordinary eye floaters that are no cause for alarm can also cause these symptoms.Full Answer >
Using an Amsler Grid eye exam is one of the simplest methods to test for macular degeneration, a condition that deteriorates the retina and inhibits vision. It does require the user to interpret the results, which might lead to an inadequate self-evaluation of the progression of the disease.Full Answer >