Visual Impairments and Blindness (VIB) - The two most common criteria used to define VIB are visual acuity and visual field.
1. Visual acuity - sharpness of vision. Measured by the ability to see small details from a given distance based on a set standard.
2. Visual Field (degrees of peripheral vision) – tells how a person sees from one side to another and from up and down. (Porter, 2015)
The prevalence of VIB increases with age, especially after the age of 75. It is one of the most common causes of a disability in the United States. (Porter, 2015) The following are potential causes for VIB:
1. Ocular VIB – a disease or condition that affects the eye. A few examples include refractive errors, age-related macular degeneration, cataract, diabetic
Another speaker, Margaret Livingstone delves into the visual aspect of our senses. Livingstone mentions how artists recognize things about vision that neuroscientists are not privy to until years later. Livingstone discussed the differentiation between color and lightness, and how the two contribute differently to a work of art. Color is thought of as “comparing activity” whereas light is thought of as “summing them.” Livingstone indicates that the visual system is subdivided into a ventral system and a dorsal system. The ventral system is responsible for object recognition, face recognition, and color. The dorsal system is responsible for navigating through the environment, special organization, and emotional recognition. The ability for humans to see distance and depth is carried via our colorblind part of our visual system. As a result, Livingstone concludes that one cannot see depth and shading unless the luminance is right to convey three-dimensional.
The immune system of a human can be weakened by a few things, but mainly illnesses and some medications such as chemotherapy and radiation. Approximately one million people a year are diagnosed with shingles, but this only accounts for the people that went to the doctor. People over the age of sixty are twice as likely to get shingles then those under sixty. The chance of getting shingles rises with age, after 60 it rises much faster. (http://www.shinglesinfo.com/risk-factors.html, 2011)
Understanding of Children with Congenital Profound Visual Impairment." British Journal of Developmental Psychology, 22.1 (2004): 1-17.
The ‘where visual pathway’ is concerned with constructing three dimensional representations of the environment and helps our brain to navigate where things are, independently of what they are, in space in relation to itself (Mishkin & Ungerleider & Macko, 1983).... ... middle of paper ... ... The 'Standard' of the 'Standard'.
According to Baily and Hall, while visual impairment early in life is associated with inherited congenital disorders, abnormal fetal devepment, and problems associated with premature birth, most eye conditions are associated with aging. They claim that over 70% of the visually impaired population in the United States is over 65. Age related maculopathy, also called macular degeneration, or AMD, impairs the center of vision in older individuals. The macula is the region in the back of the retina that surrounds and includes the fovea (Goldstein 1999). It is important to understand that when this degeneration progresses enough, the condition constitutes blindness because the foveal area is what is used to focus on something. Most cases do not progress this far, but between five and 20% do. Allikments and Shroyer claim that 11 million people in the United States alone suffer some degree of this impairment, with 75% of those individuals being 75 or older. Seven percent of this older age group reportedly suffer advanced forms. Freidman reports the disease as most common in developed countries.
Blindness is defined as the lack of visual perception. Blindness can also be defined as not being able to see things for what they really are. One may be able to see but may not be able to see the true meaning of something. Black communities often refuse to see the way that white people treat them. In Ralph Ellison’s novel Invisible Man many events contribute to the overall theme of sight vs. blindness.
"Perception - Definition of Perception by the Free Online Dictionary, Thesaurus and Encyclopedia." Dictionary, Encyclopedia and Thesaurus - The Free Dictionary. Web. 08 Feb. 2011. .
Glaucoma is a group of eye disorders that cause blindness by hurting the optic nerve, which is the large nerve that is responsible for vision. In glaucoma, the optic nerve damage is related to a change in the fluid pressure that circulates around the eyeball. In many cases, Glaucoma occurs when the eye's fluid pressure is high, but it can also occur when the pressure is measured as normal.
retina. The image that forms on your retina is flat, but you see a world of
Macular degeneration also known as late, aged-related maculopathy is an eye disorder which causes a decrease in the visual field known as the retinal macula (Medical Encyclopedia, 2000). The majority of people who are affected are people over the age of 65, but occasionally it develops earlier in people 40-50 years old (Philippi, 2000). The majority of the visual loss is located in the central part of the visual field, while the peripheral vision is unharmed. There are also two types of macular degeneration, the "wet" and "dry" forms. The "dry" form of this disease is the most popular, affecting 90% of the cases (American Academy of Ophthalmology, 1997).
Each one of us lives in our own unique world of perception. As individuals, we may experience life in an entirely different way through our senses and life experiences. Therefore, perception can be tricky since it is very personal to each one of us. According to the Merriam-Webster online dictionary, perception has three meanings; (1) “the way you think about or understand someone or something,” (2) “the ability to understand or notice something easily,” and, (3) “the way that you notice or understand something using one of your senses” (2014, para. 1). C.S. Lewis said, “What you see and what you hear depends a great deal on where you are standing. It also depends on what sort of person you are” (n.d., para. 11). In other words,
Perspective has its roots in Latin it comes from the word ‘perspicere’ or translates literally as ‘to see clearly.’
No one definition will suffice to encompass the whole definition. Visual literacy means understanding the process of formally analyzing art or architecture; identifying who, what, when, where, why, and how, along with the identifying formal elements of line, color, medium, texture, shape, and space. Visual and aesthetic qualities must also be considered: composition, movement, scale, light, mood, meaning, and style. The use of formal analysis, formal elements and visual and aesthetic qualities builds a foundation upon which a knowledgeable artist or critic forms an opinion about a piece. Normally sighted people think of visual literacy as the way in which we interpret and decode meaning in advertising, signage, art, and so on.
Perception is defined as the process of organizing, interpreting, and selectively extracting sensory information . Visual perception is left to the individual person to make up their own mind. Perceptual organisation occurs when one groups the basic elements of the sensory world into the coherant objects that one perceives. Perception is therefore a process through which the brain makes sense of incoming stimuli.
Legal blindness is defined as a measurement used primarily for eligibility for government or private assistance programs (Turnbull 2019, p. 430). In order for a child to qualify for special education and related services, his visual impairment must affect his learning. It is estimated that two students out of every 1000 have a visual impairment that interferes with learning (Turnbull 2010, p 430). According to Turnbull, there are three types of visual impairments: Low Vision, Functionally Blind and Totally Blind (Turnbull 2010 p 431).