Search results
Results From The WOW.Com Content Network
Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficulties with normal daily tasks, including reading and walking. [6] The terms low vision and blindness ...
Optics and vision. Vision of humans and other organisms depends on several organs such as the lens of the eye, and any vision correcting devices, which use optics to focus the image. The eyes of many animals contains a lens that focuses the light of its surroundings onto the retina of the eye. This lens is essential to producing clear images ...
Far-sightedness, also known as long-sightedness, hypermetropia, and hyperopia, is a condition of the eye where distant objects are seen clearly but near objects appear blurred. This blur is due to incoming light being focused behind, instead of on, the retina due to insufficient accommodation by the lens. [6]
JAMA Ophthalmology: In 2016 JAMA Ophthalmology conducted a study involving 12 legally blind participants to evaluate the usefulness of a portable artificial vision device (OrCam) for patients with low vision. The results showed that the OrCam device improved the patient's ability to perform tasks simulating those of daily living, such as ...
People with Type 2 diabetes are already at an increased risk for vision problems, including NAION. Another vision problem, diabetic retinopathy, is the leading cause of blindness in adults and is ...
Eye examination for visual acuity. Visual acuity is a measure of the spatial resolution of the visual processing system. VA, as it is sometimes referred to by optical professionals, is tested by requiring the person whose vision is being tested to identify so-called optotypes – stylized letters, Landolt rings, pediatric symbols, symbols for the illiterate, standardized Cyrillic letters in ...
Trichromacy or trichromatism is the possession of three independent channels for conveying color information, derived from the three different types of cone cells in the eye. [1] Organisms with trichromacy are called trichromats. The normal explanation of trichromacy is that the organism's retina contains three types of color receptors (called ...
Scotopic vision. In the study of visual perception, scotopic vision (or scotopia) is the vision of the eye under low- light conditions. [ 1 ] The term comes from the Greek skotos, meaning 'darkness', and -opia, meaning 'a condition of sight'. [ 2 ] In the human eye, cone cells are nonfunctional in low visible light.