Chapter 10: Blindness & Low Vision Flashcards
Visual Acuity
the ability to clearly distinguish forms or discriminate among details
Legal blindness
Visual acuity of 20/200 or less with glasses (At 20 ft someone something a non/blind person could see at 200 ft)
Partially Sighted
Visual acuity improves after correction in one eye between 20/70 and 20/200
IDEA Definition
Visual impairment including blindness means an impairment in vision that, even w/correction, adversely affects a child’s educational performance. The term includes both partial sight and blindness
Classification of Visual Impairments for Educators (4)
-Educators classify students w/visual impairments based on the extent to which they use vision and tactile and auditory sense for learning
-Totally Blind: no info through vision, uses tactile and auditory senses for learning
-Functionally Blind: learns primarily through tactile and auditory senses for learning
-Low Vision: Vision as primary means of learning, but supplements w/tactile and auditory input
Characteristics (5)
-Children who are blind perform more poorly on cognitive tasks requiring comprehension or relating different items of info
-Abstract concepts, analogies, and idiomatic expressions are difficult for children who can’t see
-Deficits in motor development and increased risk of falling
-Blind often interact less and are often delayed in the development of social skills
-Blind have stereotypy (body rocking, hand flapping, etc.)
Prevalence (4)
-Visual impairment requiring spec ed is a low incidence disability
-fewer than 2 in 1000 of school-age population
-1 in 250 school-age children w/IEP are served under visual impairment category
-Many students w/visual impairments have other disabilities that they are classified under
Anatomy/Physiology (4)
-They eye’s muscular system enables ocular mobility: movement of eye
-Binocular vision: ability to fuse the separate images from each eye into a single 3D image
-The eye’s nervous system converts light energy into electrical impulses the brain can understand
-The eye’s optical system collects and focuses light energy reflected from objects in the visual field
-Cornea, aqueous humor, pupil, iris, lens, vitreous humor, retina
Pathway of Vision (7)
Cornea, Aqueous humor, pupil, iris, lens, vitreous humor, retina
Refractive Errors (Cause) (4)
-Refraction: process of bending light rays when they pass from one transparent structure to another
-Myopia: nearsightedness, image falls in front of retina instead of on it
-Hyperopia: farsightedness, light rays don’t converge on retina
-Aided w/glasses or contacts
Structural Impairment (Cause) (6)
-Damage/poor development/malfunction of eye’s optical or muscular systems
-Cataract: cloudiness in lens that blocks light
-Glaucoma: abnormally high pressure in the eye caused by blockages of fluids in the eyes
-Nystagmus: rapid, involuntary, back-and-forth movements of the eye
-Strabismus: inability to focus on the same object with both eyes b/c imbalance of eye muscles creates an inward or outward deviation of eye(s)
-Cortical Visual Impairment (CVI): reduced visual functioning due to known or suspected damage to or malfunction of the parts of the brain that interpret visual info
Educational Approaches (11)
-Braille for literacy and some math
-Manipulatives such as rods to learn length/math concepts
-For science and social studies students are taught to use tactile and auditory senses for first hand manipulation and discovery
-Technological aids for reading print
-Teach keyboarding
-Systematic training in visual recognition and discrimination to learn their visual impressions intelligently and effectively to understand what they see
-Large print materials and optical devices
-Classroom adaptations (lighting, writing paper that reduces glare, etc.)
-Orientation and Mobility instruction
-Development of listening skills
-Functional life skills
Placement
-68% of school-age w/visual impairments in reg classroom
-12% resource rooms
-9% separate classrooms
-11% other such as residential schools
-3% residential schools which should not be permanent
Expanded Core Curriculum (6)
-Orientation and Mobility
-Listening Skills
-Social Interaction Skills
-Independent Living Skills
-Recreational and Leisure Skills
-Career Education
Visual Efficiency
-Denotes how well a person can use whatever amount of vision they have.
-Includes skills such as fixating and locating, discrimination, awareness, tracking, etc.
