Sobre a Deficiência Visual

Science for Students with Visual Impairments:

Teaching suggestions and policy implications for Secondary Educators

by David D. Kumar, Rangasamy Ramasamy & Greg P. Stefanich

 3-D Cell Models of some cell structures
3-D cell models of some cell structures


Summary | Science educators should realize the student-oriented benefits of science learning and make every effort to accommodate students with visual impairments in science. An awareness of the legal rights, and an understanding of the academic needs of visually impaired students are essential in striving towards this goal. Unless science educators stress the need for science for the visually impaired students in their science teacher education programs, and science teachers make necessary efforts to accommodate them in their instruction, it is extremely difficult for students with visual impairments to gain an equitable exposure to science education. Full participation in science by visually impaired students, as well as students with other disabilities, will be beneficial for all students, and a rewarding experience for teachers.



The education of students with exceptionalities is an area of emphasis in education reform. Research (Ferguson & Asch, 1989; Baker, Wang, & Walberg, 1994) is consistent that students with disabilities who learn in regular classrooms often outperform their counterparts who experience academic instruction in segregated settings. General students benefit as well (Costello, 1991; Kelly, 1992, Straub & Peck, 1994) yielding social and emotional benefits for all students. As a result, it is critical that teachers need more than ever before to understand students with diverse exceptionalities, their characteristics, their needs, and effective strategies to work with them (Friend & Bursuck, 1999). However, students with disabilities are not adequately accommodated in science instruction and the condition of science education for these students remains very discouraging.

The amount of time spent on science in the case of students with mild disabilities is considerably less than that spent on reading instruction (Ysseldyke, Thurlow, Christenson, & Weiss, 1987). According to Patton, Polloway, and Cronin (1990), 38% of special education students hardly receive any instruction in science, and 90% of teachers who teach science to students with special needs often employ text-book centered teaching. According to Pawmar and Cawley (1993), in most commercial textbooks suggestions for teaching students with disabilities are noted in isolation without reference to the concurrent activity of other students.

Therefore, the general classroom teacher cannot rely on textbook publishers for suggestions for addressing the needs of students with visual impairments in regular classrooms. Stefanich and Norman (1996) in a national survey found that most science teachers and college science educators "have had little or no direct experience in teaching disabled students," and they "do not expose the students in methods classes to instructional strategies best suited for participation by all students" and "often hold stereotypical views of what students with disabilities can and cannot do" (p. 51).

Nevertheless, with respect to students with visual impairments, the Stefanich and Norman's (1996) survey found that 73.7% of K-12 science teachers and university science educators disagreed with the statement that "I am more comfortable in a setting in which there are no people with visual disabilities" (p. 19). Also, 69.8% of those surveyed did not believe that "it is unrealistic to expect a blind student to be a chemist" (p. 18). Science is a process of exploring the universe, and it has student-centered benefits (e.g., development of cognitive skills) essential to personal growth of all students including those with disabilities.

The Individuals with Disabilities Education Act (IDEA) in the United States require that students with disabilities receive full access to education. According to the American Association for the Advancement of Science (AAAS) (1991) "the full potential of many of the students with disabilities are not yet being realized" (p. 8).

How to increase the participation of students with disabilities, especially those with visual impairments in science education, is a critical issue. For the purpose of this paper the term visual impairment, including blindness, is based on IDEA and is defined as "an impairment in vision that, even with correction, adversely affects a child's educational performance" (p. 598), and may be broadly classified as low vision, functionally blind, or totally blind (Turnbull, Turnbull III, Shank, & Leal, 1995).

Suggestions for Teachers

It should be pointed out that students with visual impairments have the same range of cognitive ability as other students. However, since school learning relies very heavily on vision, students with this disability frequently experience academic problems. They must be exposed to a variety of experiences in science that can reasonably be explored.

Although, visual disabilities tend to restrain individuals from highly variable experiences, overcoming barriers to experiencing activities that are unfamiliar is critical in stimulating the intellectual growth of students with visual disabilities.

In order to accommodate students who are visually impaired in science classrooms and laboratories, teachers should consider the following suggestions synthesized from AAAS (1991), Cetera (1983), Dubnick (1994), Lunney and Morrison (1981), Smith (1998b), Smith, Polloway, Patton, and Dowdy (1998), Wagner (1995a), Wohlers (1994), Ricker (1981), and Ricker and Rodgers (1981).

  • Translate course syllabi and materials into Braille and adaptive electronic media.
  • Allow lectures to be audiotaped.
  • Encourage direct conversation and speak directly to the visually impaired individual in a normal tone of voice.
  • Refrain from using vague phrases. For example, be specific when giving directions - please take the centimeter ruler and measure the length of the pendulum.
  • Provide large print copies of written materials for students with partial visual impairments. As far as possible increase visual contrast of written materials.
  • Provide a wide range of hands-on learning experiences. Use real objects so that the student can feel them by touch.
  • Allow students to explore in their natural environment, for example, plants, animals, and muddy boundaries surrounding a pond.
  • Supply students with tactile diagrams and graphs (by outlining with liquid glue). Use appropriate scale whenever possible.
  • Orient the visually impaired student by familiarizing him/her with emergency exits, chemicals, glassware, equipment, extinguishers, emergency showers, and eye sprays. Perhaps this orientation might be best achieved by partnering the visually impaired student with a volunteer in class.
  • Use Braille labels on chemicals and reagent containers.
  • Keep the laboratory aisles cleared, and do not leave doors half-open. Instruct other students in class to yield the right of way to the visually impaired student whether or not that student is using long canes.
  • Provide ample space for the guide dog, if one is involved, and keep other students from harassing the dog.

If possible, provide a laboratory assistant or find a volunteer in class who is willing to work with the visually impaired student to read directions and procedures, and guide him/her through activities.

Provide assistive technologies whenever possible. Examples of assistive technologies recommended by AAAS (1991) include talking thermometers, voltmeters, timers and calculators, glassware with embossed numbers, sandpaper labeling for poisonous chemicals, and computers with voice or Braille output. Light probes and special adapters which transform visual and digital signals into audio outputs are also suitable for assisting the visually impaired student in science laboratory settings.

For information about sources of materials for students with visual impairments, Lewis and Doorlag (1998) suggest the following web sites of the corresponding organizations:

American Foundation for the Blind (www.afb.org), National Federation of the Blind (www.nfb.org), American Council of the Blind (www.acb.org); National Association for Visually Handicapped (www.navh.org), American Printing House for the Blind, Inc. (www.aph.org), and the Blindness Resource Center (www.nyise.org/blind.htm).


The following examples show how some of the suggestions listed above could be implemented in the physical, chemical and biological sciences to accommodate students with visual impairments in science instruction.

Physical Science

There are innovative ways physical science could be made accessible to students with visual impairments. Wagner (1995b) described how to prepare tactile measuring tools for visually impaired students. For example, photocopy sections of a meter scale onto transparencies, and cut and paste the sections into a meter long scale, and staple or use glue to emboss each centimeter marking. The visually impaired student could use this tactile scale to practice measuring objects. According to Wagner (1995b) such measurement activities should help students with visual impairments "gain self confidence in a skill easily transferable to real life" (p. 77).

An activity, developed by the Center for Multi-sensory Learning, for determining mass using a modified lever balance (cited in Carin, 1993) is as follows. Cut out the bottom of the two pans of a lever balance making rings suitable for holding paper or plastic cups. Add a tactile balance indicator. Materials to be weighed automatically center in the cups, thus reducing discrepancies caused by relative positioning. Also substances weighed, both solids and liquids, can be kept in the cups, an added convenience in transferring of materials. This modified balance could be used to verify that the mass of 50 ml of water is approximately 50 grams, and to understand the relationship between mass, volume and density of water.

Chemical Science

There are many ways visually impaired students could be accommodated in chemical science. According to Wohlers (1994) computer interfaced instrumentation provides tools for mass-volume measurements in chemical laboratories. Talking calculators are suitable for handling quantitative calculations.

Qualitative identifications of certain non-hazardous materials could be made using the sense of smell (Keller, Jr., 1981).

Chemical reactions involving colors can be identified using a colorimeter interfaced with a computer programmed to convert color signals into Braille outputs.

Also, light probes interfaced with Braille computers will make good detectors for determining end-points in volumetric analyses. Similarly, modified Ultra-Violet and Infra-Red spectrophotometers can be used for chemical characterization. The phase-change ink technology mentioned elsewhere in this paper might be a suitable tool for tactile spectrum outputs.

Likewise, with proper modifications, standard plastic chemical structure kits will serve as excellent tools for learning various atomic and molecular structures as well as geometries. Wagner (1995c) outlined how certain chemical reactions involving gaseous products could be carried out in zip lock bags (Wagner, 1995c). For example, mix about one level spoon of baking soda and 10 ml of vinegar in a zip lock bag, close the bag and let visually impaired students record their observations using touch and hearing and share their findings with other students.

In a similar manner, the concept of heat of reactions, both exothermic and endothermic, could be introduced using commercially available heat packs and cold packs. See Wagner (1995c) for details.

Biological Science

There are many ways biological science could include students with visual impairments. "Blind or visually impaired students have the same need for fundamental life science instruction that sighted children do" (Malone & DeLucchi, 1979, p. 29).

Tactile modifications of preserved specimens and humanely prepared living organisms (e. g., live Cray fish with rubber tubings carefully placed over their pincers) could form excellent hands-on specimens in biology (Malone & DeLucchi, 1979).

A variety of lessons on nature, ecology, animals, birds, insects and plants could be developed and taught through group activities and field trips. See Keller, Jr. (1981), and Malone and DeLucchi (1979) for specific details.

Topics such as cell division and genetics are also within the reach of visually impaired students. Ricker and Rodgers (1981) suggested how to modify chromosome kits with "pop-it beads" using easily available tactile markers for teaching cell division.

The suggested tactile markers include small plastic strips of various sizes and shapes to represent color codes, and holes to represent relative positions of chromosomes.

Abruscato (1996) recommended the following activity to enable a student with visual impairments to observe a fish in an aquarium. For example, place inside the aquarium a slightly smaller sized plastic aquarium with drilled in holes, which acts like a sieve. As the student slowly lifts the inner aquarium and drains off the water into the larger aquarium, the fish will be trapped in the bottom of the inner aquarium. Now by the sense of touch the student can explore the fish. (Supervision might be required in order to make sure that the fish is properly handled and not hurt in any way.)

Discussion and Policy Implications

The suggestions and classroom examples discussed above show how students with visual impairments could be a part of science education. According to Kami and DeVries (1993) "physical knowledge can be constructed in the child only through acting on objects, and the teachers role here must be to assist the child in this process rather than to serve as a source of knowledge" (p. 23).

In order to restructure science instruction to increase the participation of students with visual impairments, their concerns and needs must be addressed in science teacher education, science assessment, and educational technology.

Science Teacher Education

One of the ways of influencing classroom teachers to make science education accessible to students with visual impairments is through teacher education. According to the Working Conference on Science for Persons with Disabilities (Egelston-Dodd, 1995) "science faculties tend to be uninformed and often lacking in willingness to make accommodations for students with disabilities" (p. 95) and teacher education programs fail to provide field experiences in teaching students with disabilities. Both inservice and preservice teachers must be made aware of the needs of students with visual as well as other disabilities (Keller, Jr., 1994; Lang, 1983; Stefanich & Norman, 1996).

Prospective teachers must be exposed to the knowledge and uses of resource materials and adaptive technologies that facilitate the accommodation of visually impaired students in science lessons. Likewise, inservice teachers must be equipped with methods of teaching science to students with visual impairments through specialized workshops.

Science educators need to make conscious efforts to catalyze the integration of students with disabilities in science classrooms and make necessary accommodations for them to excel in science.

Science Assessment

Although testing has always been a major part of education, the recent emphasis on schoolwide testing aimed at raising educational standards in countries such as the United States necessitates that educators develop appropriate alternative testing formats for norm-referenced testing (Thurlow, Ysseldyke, & Silverstein, 1995). The need for more research and development in alternative forms of assessment for students with disabilities including students with visual impairments was one of the recommendations made by the Working Conference on Science for Persons with Disabilities held in 1993 and 1994 (Egelston-Dodd, 1994 & 1995).

"Alternative format testing and follow through on assessment to ensure equity for visually impaired students are needed reforms" (Egelston-Dodd, 1994, p. 133).

Science teachers should exercise caution in assessing students with visual impairments using carelessly prepared tests, and be willing to make necessary changes in their assessment criteria and procedures. Teachers should consider using formative hands-on assessment tasks if standardized testing procedures for the visually impaired students in a particular science topic are lacking. Efforts should be made to develop hands-on forms of adaptive tests (similar to the computerized versions) so that assessment can be tailored to determine what the individual student knows or does not know about a particular topic.

Assessment should not be used as a punitive measure; instead, it should be considered as a vehicle for helping the students evaluate their strengths and weaknesses. One very important point that teachers should keep in mind when testing students with disabilities is making sure that test results reflect their knowledge and skills, not their disabilities.

Science educators should address alternative assessment methods for students with visual impairments in preservice teacher education. Often tests may have been well written but constructed in a way that results in problems for students with visual impairments. For example, if some one has difficulty reading tests that are visually cluttered, teachers should use triple spacing between test items, extra space between lines, and allow wider margins (Friend & Bursuck, 1999).

Other suggestions for test construction include the use of symmetrical spacing. For example, when using multiple choice tests, align possible responses vertically rather than horizontally on the same page and permit students to circle the letter of the correct answer.

When implementing essay questions, dictated or taped responses for students with visual impairments should be allowed. Also, teachers should consider color coding, underlining, enlarging, or highlighting key words and symbols (Friend & Bursuck, 1999).

Educational Technology

In recent years science curriculum reform efforts have stressed the integration of educational technology into teaching, learning and assessment. Science educators should explore ways in which new technologies could be utilized to improve access to science instruction for students with visual impairments.

Technological resources for the visually impaired include Braille generating software, scanners, Braille printers and embossers, screen-reader software, speech synthesizers, and closed circuit television. A few examples of these technologies are as follows.

Optacon and Optacon II are devices which help to convert scanned in information on a paper or computer screen into tactile letters (Hallahan, & Kauffman, 1991). Kurzweil Reading Machine is used to convert ordinary print information into synthesized speech (Hallahan, & Kauffman, 1991). VersaBraille is useful for recording Braille onto audio tapes and reproducing them on a Braille reading board while VersaBraille II is used to convert letters on a computer screen into Braille (Hallahan, & Kauffman, 1991). Videotapes with Descriptive Video Service (DVS) are used to provide students with visual impairments auditory descriptions of videos (Wagner, 1995a).

A new "phase-change ink technology" reported by John Garner of Oregon State University may help to reproduce mathematical symbols and notations in raised line Braille formats (Wohler, 1994).

The 1994 Working Conference on Science for Persons with Disabilities (Egelston-Dodd, 1995) noted a gap between the availability and use of technologies in schools, a shortage of fiscal resources to acquire technologies, and a lack of training in the use of new technologies to support instruction. It should be made clear that it is not the mere presence of technological resources but their implementation in science education which facilitates access to science learning for the visually impaired students. As Sutherland (2000) said, "a series of flash cards mounted on a ring and used every day is superior to a new computer with all the bells and whistles that sits in a corner because the teacher has no time to integrate its use into classroom activities" (p. 30).

To make internet and computer technology available to visually impaired students, it is imperative that the principles of "universal design" be followed. Universal design means, that, rather than designing a facility for the average user, it should be designed for people with a broad range of abilities and disabilities (Adaptive Environments Center,Inc., 2000). Examples of universal design in the area of computer technology include key boards with Braille labels, and anti-glare computer screens.


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About the authors...

Dr. David Kumar is a professor of Science Education at Florida Atlantic University. He is co-editor of the book Science, Technology, and Society: A Sourcebook on Research and Practice (Kluwer Academic/Plenum Publishing, New York, 2000).
Dr. Rangasamy Ramasamy is an associate professor of exceptional student education at Florida Atlantic University in Boca Raton. He earned his Ph.D from the University of Arizona. At FAU, he teaches courses in general special education, classroom management, and applied behavior analysis. His publications and research interests focus on transition from school to work, Native American education, inclusive education, and applied behavior analysis for students with disabilities.
Dr. Greg Stefanich is a professor at the University of Northern Iowa. His primary teaching responsibilities include science methods and program evaluation courses. In recent years his scholarship has been directed towards improving inclusive practice in science education. He has been a recipient of the Ross A. Nielsen Distinguished Service Award (1998), Distinguished Scholar Award (1994), and Regents Award for Faculty Excellence (1993) from the University of Northern Iowa and the Presidents Award from the National Middle School Association (1981).



'Science for Students with Visual Impairments:
Teaching Suggestions and Policy Implications for Secondary Educators'
   David D. Kumar (Florida Atlantic University)
   Rangasamy Ramasamy (Florida Atlantic University) and
   Greg P. Stefanich (University of Northern Iowa)

source: http://wolfweb.unr.edu/homepage/crowther/ejse/kumar2etal.html




publicado por MJA