There are two main functional categories of visual impairments: Low Vision and Blind. Low vision students usually are print users , but may require special equipment and materials. The definition of legal blindness covers a broad spectrum of visual impairments. The extent of visual disability depends upon the physical sensory impairment of the student's eyes, the age of the student at the onset of vision impairment, and the way in which that impairment occurred. Vision also may fluctuate or may b e influenced by factors such as inappropriate lighting, light glare, or fatigue. Hence, there is no "typical" vision impaired student. The major challenge facing visually impaired students in the science educational environment is the overwhelming mass o f visual material to which they are continually exposed, viz., textbooks, class outlines, class schedules, chalkboards writing, etc. In addition, the increase in the use of films, videotapes, computers, laser disks, and television adds to the volume of v isual material to which they have only limited access. To assist in overcoming a students' visual limitation requires unique and individual strategies based on that student's particular visual impairment and his/her skill of communication (e.g., Braille, speed listening, etc.). (After: "The Mainstream Teaching of Science: A Source Book", Keller et al.)
The degree of impairment and the student's background and training (like the degree of proficiency in Braille) will affect the usefulness of the various strategies and suggestions. The student with a vision impairment will most likely need assistance in all aspects of science programs. The various strategies given below will work for most vision impaired students--some may not. Accessible description will be necessary for pictures, graphics, displays, or field sites, etc.; the student's identification queries; and differentiation of items where touch will not discriminate; and in orientation and mobility aspects in unfamiliar situations.
1) Describe and tactually/spatially familiarize the student with the lab and all equipment to be used.
2) Consider alternate activities/exercises that can be utilized with less difficulty for the student, but has the same or similar learning objectives.
3) Use an enlarged activity script, directions, or readings for a low vision student (or taped script for a student who is blind) for use with tactile 3D models.
4) Make all handouts and assignments available in the appropriate form for the student: e.g., regular print, large print, Braille, or tape depending on the students optimal mode of communication.
5) Assistance may be needed for converting certain laboratory materials from a visual to a tactile format.
6) Have the student with a vision impairment do a trial run on the equipment before the activity.
7) Allow more time for the laboratory activities.
8) Always try to keep materials, supplies, and equipment in the same places.
9) Use a microprojector or similar device to help the visually impaired student to examine images from a microscope.
10) Place the student and/or tape recorder an appropriate distance from the activity to permit hearing and/or the recording of results or observations.
11) Use an overhead projector or opaque projector to show step-by-step instructions. Mask all the instructions except the one(s) that you want followed for students with vision impairments.
12) Use Descriptive Video for videos or laser disks. If Descriptive Video is not available, use a sighted narrator to describe movies, videos, laser disks, or slides.
13) Provide means for the acquisition and/or recording of data in an appropriate mode for the student.
14) Use tag shapes for showing relationships (such as distance comparisons) buttons, or other markers on a "layout" board.
15) A Braille label maker will be useful for identifying materials and containers in the laboratory for the vision impaired student with a vision impairment who reads Braille.
16) Make equipment available that the student with a vision impairment can access in interpreting and understanding the results of laboratory exercises (e.g. audible readout voltmeters, calculators, talking thermometers, magnifiers, etc.
17) Use a hot plate for heating instead of Bunsen burner.
18) Label material, supplies, and equipment with regular print, large print, and/or Braille, as appropriate for the vision impaired student.
19) Pair the student with a vision impairment with a sighted student. Then have the non-impaired student describe the activities and outcomes as they are observed.
20) A low vision projection screen can be use to magnify images up to 720X.
21) Use a portable communication board to provides auditory scanning of laboratory materials such as: pictographic symbols, letters, and/or words.
22) When using a computer, the student with a visual disability can use a voice input device or a remote voice system to verbally enter commands.
23) Prior to the enrollment of a student with a visual impairment in class, obtain laboratory equipment that have available ability to produce adaptive outputs such as: a large screen, print materials, or various audio output devices.
24) Various Braille devices can be used to assists vision impaired students when reading.
25) For "reading" the outputs of balances and other instruments, one can use a Braille N' Speak device (Blazie Engineering)
26) Have a lab assistant help you if necessary to make sure that students with visual impairments are being assisted.