Visual science is the study of how people see and process visual information. It encompasses a wide range of topics, from the physiology of the eye to the psychology of perception. Researchers in visual science use a variety of techniques, including experiments, mathematical models, and computer simulations.
The eye is the organ that enables vision. It is a complex structure, consisting of the cornea, lens, retina, and other parts. The cornea is the transparent outer layer of the eye. It bends (refracts) incoming light rays so that they focus on the retina—the sensitive inner surface of the eye where images are formed. The lens is a curved piece of clear tissue behind the cornea that further refocuses light rays onto the retina. The retina consists of several layers containing light-sensitive cells that convert light into electrical signals. These signals are sent through nerve fibers to the brain, where they are interpreted as images.
The ability to see depends on many factors, including our eyesight (acuity), pupil size, depth perception, color vision, and contrast sensitivity. Our eyesight can be measured using an eye chart; those with 20/20 vision can read letters at a distance of 20 feet that most people can read at that distance. Pupil size affects how much light enters our eyes and thus how well we see in dim lighting conditions; smaller pupils admit less light than larger ones do. Depth perception refers to our ability to judge distances between objects and estimate their sizes; it requires both eyes to work together (binocular vision). Color vision enables us to see different colors; it arises from special cells in our retinas called cones which are sensitive to different wavelengths of light (longer wavelengths appear red while shorter wavelengths appear blue). Contrast sensitivity refers to our ability to discern small differences in brightness or color; it too depends on having healthy cone cells in our retinas.
There are many disorders that can affect our vision. Myopia (nearsightedness) occurs when distant objects appear blurry because they are focused in front of rather than directly on our retinas; this problem can be corrected with glasses or contact lenses which help refocus incoming light rays onto our retinas . Hyperopia (farsightedness) results when close objects look blurry because they are focused behind rather than directly on our retinas; this too can be corrected with corrective lenses . Astigmatism occurs when an irregularity in either the shape of one’s eyeball or one’s cornea causes distortedvision ; once again , corrective lenses may help alleviate this problem . Other common disorders include glaucoma , cataracts , macular degeneration , and diabetic retinopathy . Early detection and treatmentof these disorders is important for preserving one’s vision .
Visual science plays an important role in helping us understand not just how we see but also why we see what we do—including both normal and abnormal vision . By better understanding how we process visual information , researchers hope to develop new ways to treat various visual disorders .