Issues Regarding the Assessment of Vision Loss in Regard to Sign Language and
Fingerspelling for the Student with Deaf-Blindness.

by Robbie Blaha, Education Specialist, TSBVI Deaf-Blind Outreach.



When a child is deaf or hard of hearing, his access to information and interaction relies heavily on the visual channel. Since sign language and fingerspelling are intensely visual in nature, vision loss affects the childís ability to access and acquire these communication forms. For this reason, it is important to address any vision loss which might impact the studentís ability to access educational information.

The effect of the studentís vision loss on the acquisition and use of visual communication forms needs to be evaluated so that appropriate adaptations can be implemented. The communication assessment, Functional Vision Assessment, or Learning Media Assessment (LMA) do not routinely address this issue. Because this issue is so complex, assessment of vision must be carefully planned for and carried out.

Working with educators in Texas, we have developed an approach to evaluating the impact of vision loss on the childís ability to access and learn information through these communication forms. I wanted to share this information, hoping it might be useful to others facing the same task.


Assemble the assessment team

Obtaining the information that is needed requires a team approach. The evaluation process requires someone who can understand what the child is signing, what is being signed to the child, and what specific visual obstacles must be over come for the child to learn and use these forms of communication. Specifically, the team needs to include both a teacher of the visually impaired and a teacher of the deaf or hard of hearing. Both these teachers have critical information that the other lacks, requiring collaboration between them.

The team may also need support from a professional with a background in deaf-blindness. Specific training on the assessment and development of programming for students with deaf-blindness is not covered in training programs for teachers of the visually impaired or for teachers of the deaf or hard of hearing. This information is peculiar to the field of deaf-blindness. In addition, the classroom interpreter is trained to provide services to individuals who are deaf or hard of hearing, but may also be unfamiliar with the adaptations needed for the deaf-blind child to access these forms of communication.

Conduct standard screenings/assessment

The process of evaluating the effects of vision loss on recognizing and using visual forms of communication is tied to the Functional Vision Assessment and the Learning Media Assessment (LMA). Conducting these assessments is the primary responsibility of the teacher of the visually impaired in collaboration with the team. As a team you should determine how to gather this information. The teacher of the visually impaired can report the impact of the studentís vision loss on signing and fingerspelling in either the Functional Vision Assessment or LMA.

Compile information

After the Functional Vision Assessment is completed, the team needs to compile some specific information.

1) What is the childís etiology?

There are a number of syndromes which have both a vision and hearing loss. This may have bearing on the best educational approaches to use with the child or give direction to long-term medical follow-up. For example, Usher Syndrome brings about a visual field loss. Children with Congenital Rubella syndrome have a risk of developing cataracts and glaucoma. Resources such as the National Organization for Rare Diseases (NORD) and D-B Link can be very helpful in obtaining this important information. There are other etiologies besides syndromes that can cause vision loss. An example of such a condition is spinal meningitis. Cortical visual impairment (CVI) can be associated with this condition and results in fluctuating vision and possible perceptual problems.

2) What communication system or methodology is being used with the child?

There are several manual communication methodologies or systems being used in Texas classrooms at this time. A sentence or thought can be expressed in different ways, depending on which communication methodology or system is used, resulting in different visual demands on the child. Chart 1 gives some very simple definitions of these methodologies or systems. (Chart 1 is not comprehensive and only meant to introduce you to these terms. It is not meant to be an endorsement or criticism of any of these methodologies or systems.)


CHART 1 - Manual Communication Systems and Methodologies


American Sign Language: (ASL): "the native language of thousands of Deaf people who have Deaf parents. For them, it is not only a first language but also carries with it the culture of generations of Deaf people in America. Like other foreign languages, it has its own history, idiomatic expressions, structure and grammatical rules." It is a highly sophisticated visual language and it is not based on nor is it derived from English.-- (Humphries, et al 1980.)

Signing Exact English (S.E.E. signs): A sign system developed in the early 1970's which is based on the English Language. "The most important principle in Signing Exact English is that English should be signed in a manner that is as consistent as possible with how it is spoken or written...." (Gustason, et al 1993.)

Fingerspelling: Individual letters of the alphabet are produced manually by the dominant hand through specific handshapes. In this country, we typically use the American One Hand Manual Alphabet. It can be used in conjunction with sign language.

Total Communication (TC): English is spoken and signed simultaneously using English syntax and grammar.


Observe the child

There are tests designed to check for receptive sign vocabulary. However, these tests typically give the student the advantage of seeing one sign at a time, from a consistent distance, and with a limited number of responses. The results may accurately indicate the signs that the child knows in a clinical environment, but tell you nothing about his ability to recognize them in other environments or situations. His vision loss may impede his "functional" comprehension of these communicative forms.

Therefore, you must observe the child in these real environments and situations. Typically, we have taken the questions which follow and let these guide our observations of the child in a variety of interactions throughout his regular day. These observations are carried out over the course of several days so that we can get a broad sample of the childís functioning.

A note of caution about what you observe: It is possible to overestimate a child's receptive communication skills. For example, the student may be able to tell that someone is signing without actually discriminating discrete segments of the sign or signs. For example, the teacher holds up a yellow art folder and signs "Time for art". Twenty feet away, he can see the art folder, note the teacher was signing, and guess that she was telling him to go to art. That does not mean this child can discriminate all signs at twenty feet.

Since this guessing method works best in familiar routines, you might expect to observe a significant drop in the child's comprehension of sign language in new situations and environments. He may require different instructional distances to read signs without contextual cues or when presented with novel information.


What follows is the list of questions that guide the observations along with some considerations and possible modifications, adaptations, or teaching strategies that may be considered. This list is by no means comprehensive. There may be other questions your team wants to address. The adaptations you select are highly individualized and should be based on the individual childís vision and signing preferences.

1) What is the best signing/fingerspelling space, placement, and distance for the child related to his visual fields?

As a rule of thumb, manual communication takes place within a two foot cubic area. Students with field losses (blank spots) in their vision can have considerable difficulty in seeing signs depending on the location and size of their field loss. Missing parts of the message can greatly affect comprehension. It is important to know the child's best area for viewing manual communication. In order to make this determination, you will need to know the best placement (e.g., central, upper, left, or right quadrant) and signing space (e.g., a radius of 10 inches) for that child. If the student has a field loss, moving further away from the signer, allows him to see more of their body and provides him more of the signed information. When a child has both an acuity problem (blurred vision) and a field loss, finding the best distance becomes a much more complex issue.

In your observations, take note of a student who keeps backing up, when you try to sign to him. He may be trying to see more of you in his reduced fields. Also watch for students who touch your wrist or hand, reach out to reposition your hand, pull their head back or use eccentric viewing positions (e.g., always turns head down and to the left to use their peripheral vision). Teachers may report having trouble getting the child's attention from a particular side. Try systematically signing from different distances and locations within a quadrant. Compare these observations with the information obtained from the Functional Vision Assessment. Do they confirm where the best viewing area is for the child?

Adaptations you would consider:

2) What is the best distance and rate related to acuity for signing and fingerspelling to enable the child to efficiently read in different instructional or conversational situations?

The appropriate distance and rate for signing and fingerspelling can vary according to the complexity of the exchange, the amount of contextual support to aid in guess work, and the characteristics of the individual sign or letter. Some signs are very concrete and have big, clear movements (e.g., "brush teeth"). Some signs are more abstract and have subtle, less discernible movements (e.g., "seven"). Signs may also resemble each other (e.g., "purple" and "green"). When fingerspelling, the hand stays in one place eliminating the types of cues many signed words provide. For example, "king" is distinctive because of the movement from shoulder to hip. Also, some fingerspelled letters are remarkably similar for people with acuity losses (e.g., a, t, n, m, o, s, e). The typical rate for fingerspelling is a rapid 3-4 letters per second and this may present a problem for the child who is visually impaired.

Distance from the signing partner also must be considered. If the student has acuity problems, he will have to be close enough to his partner to bring the personís hands, face, and torso into focus. The appropriate distance and rate of signing or fingerspelling is based on the childís rate of comprehension and can vary across settings.

When you put any number of signs (and/or fingerspelled words) together, you may need to sign more slowly and distinctly. This is very difficult to do when you have other students to consider. However, you must find the approximate rate that is most visually accessible to the child with vision impairments.

Adaptations you might consider:

3) Can the student visually discern movements which give meaning to the signs?

In ASL you use an intricate combination of manual sign and nonmanual signals. These must be viewed simultaneously because the nonmanual signal alters the meaning of the sign. A few examples of nonmanual signals are: pursed lips, puffed cheeks, a raised eyebrow. When specific signals combine with the manual sign for a word, the meaning changes. (Baker & Cokely, 1980) The child can perhaps see the large hand movements, but not be able to see the more subtle movement of the eyebrow. Therefore, he misinterprets what is said.

Look at the childís overall comprehension of information that is being presented. Also consider the childís ability to read peoplesí moods or intents communicated through body language. Try some imitative games which require the child to be able to attend to facial movements and hand or body movements at the same time. Do they see both movements at a variety of distances?

Adaptations you might consider:

4) Does lighting affect a studentís ability to visually access information?

For some children, dim or very bright lighting may present challenges. As one friend who has visual impairments put it, "Light can either be my best friend or worst enemy."

Observe the childís ability to understand and respond to manual communication in different lighting conditions. Watch for changes in skills as he moves indoors and outdoors, under fluorescent lights and incandescent lights, in shaded or dimly light areas, etc. Some information should be gathered in twilight or at night.

Adaptations you might consider:

5) Does the visual background affect the childís comprehension?

Professional sign language interpreters wear dark solid colors when interpreting because it provides good contrast to their hands. This makes their signs clearer and easier to read.

The child with visual impairments has to work harder to pick out visual information when there is a "busy" visual background. Watch to see if the child's comprehension skills increase or decrease when decoding signs against different visual backgrounds.

Adaptations you might consider:

6) Does the student have skills to advocate for the modifications he needs?

Many children, even at a very young age, will let you know when they can not see what you are signing. They may pull away from tasks or refuse to look. The older child may move your hands so they will be in his field of vision or become critical of your signing. Note how well the child can assess his ability to see in any given situation and how well he can communicate visual difficulty to others. Ultimately, only the individual with deaf-blindness knows what really aids him in accessing communication and he must be able to advocate for these adaptations throughout his life.

Adaptations you might consider:

7) Can a student follow signed conversations in group settings?

Group instruction poses different demands on a childís functional use of vision than when he is in one-on-one situations. In a group lesson a teacher may start signing a sentence directly to the student at 6"-12" and then turn to another child to finish the statement. Suddenly the teacherís hands have moved to a distance of 30" from the child. When this occurs, the student with a vision loss misses part of the sign(s) simply because it has moved out of visual range.

The distance and angle of the manual communication continually changes as different people in the group take part in the discussion. The student is constantly having to locate the person signing and refocus to see what is being signed. He may even need to physically reposition himself to bring that person into view.

Taking the additional time to provide even the most basic adaptations necessary to include the child with deaf-blindness will frequently break up the momentum of a group lesson. You may know the child needs additional time to study pictures, needs other people to sign more slowly, or has trouble tracking the movement of hands. However, consistently making these changes, while conducting group instruction, may be impossible. As a result, it is easy to deny the same level of instruction to the child with deaf-blindness.

Adaptations to consider include:

Donít forget to talk with the student. In many cases he may be the best person to tell the team about problems he is having. However, it is important to remember that some children are not aware they are missing information in certain situations.

Once you have formulated a theory about how the child is using his vision, you can devise some situations to test your theory. The results may suggest the specific adaptations you want to try. These adaptations are likely to be very individualized not only from child to child, but from situation to situation for an individual child. This occurs because one individual may be effected by different lighting conditions, the degree of familiarity with a situation, the number of other visual demands being made, etc. If the child has a progressive or a fluctuating vision loss, then the adaptations he requires may also vary over time or within a short period of time.


After addressing the first group of questions, conducting interviews with staff and family, and reaching some conclusions about the childís visual functioning, we often find that we need to ask some additional questions.

8) Would the student benefit from supplemental experience work to assist in understanding the concepts behind the signs?

Children who are deaf or hard of hearing have a wealth of incidental visual information to serve as a basis for language. This may not be the case for a child with deaf-blindness. Significant amounts of this critical information are distorted or missing altogether for a child with a concurrent visual loss. For example, this child may never be able to see a bird flying or sitting in a tree, or for that matter see a "bird" at all. Showing him a picture or giving him a sign for bird assumes he knows not only what the symbol represents, but has a concept of "bird." This may not be true for him.

New information should not be introduced on a picture or sign level if the child does not have a firm experiential base to relate to the picture or sign. Even though he may have the ability to understand or remember information, if he is not getting all the information in the first place, it is virtually impossible for him to understand. This is an access issue. Children with deaf-blindness need extensive, organized experiences with real objects and actions before they can truly understand pictures, fingerspelling, or signs which represent these objects and actions. Their sensory losses have denied them this experience.

Even if the child has a good experiential base, there still may be a need for supplemental experience work. Demonstrations and modeling are used extensively with deaf or hard of hearing students. If the student cannot see the demonstration, he needs to do the action himself. For students with field restrictions, who can see the demonstrations, watching demonstrations while simultaneously attending to signing requires rapid shifts of gaze. In the process, parts of information from both sources may be lost. Objects may need to be examined tactually and visually before they can be recognized when viewed at distance. The child with acuity loss may also miss information or receive distorted information. Class demonstrations may prove equally difficult for him.

Adaptations you might consider:

9) Is the child's vision such that he would benefit from the technique of coactive signing when learning new signs?

Coactive signing is a technique which teaches expressive sign skills to students who are visually impaired and unable to see the instructor model the sign. When teaching a sign, the instructor takes the students hand(s) and helps the student form the sign correctly. This technique can also be used with students who have visual perceptual problems because these children may not be able to learn to produce signs just by watching others. While coactive signing teaches the child to make signs, he will still need to learn to read signs when others produce them. Therefore, it is important to give the child an opportunity to see (or tactually read) you make the sign if they are to learn the sign receptively.

The SKI*HI Institute has produced 12 videotapes which help family members and professionals use coactive signing effectively. (Watkins, 1991)

10) Does the child initiate or benefit from (tactual) tracking?

(Tactual) tracking when used in reference to signing occurs when the person with deaf-blindness places his hand(s) on the wrist(s) area of the signer. This technique enables a person with a visual impairment to know where the signer's hand is moving so that he can direct his gaze accordingly. He may also get enough information from the plane or general location of the hand to recognize the sign without seeing it clearly. Tactual tracking can also be used in conjunction with the other adaptations mentioned in question #1.

Some children initiate this technique on their own. This is usually an indication that they need more information than they are getting visually. Sometimes this can be a tip-off to a field loss. (Tactual) tracking should be on this child's lists of strategies since there are some situations where the strategy of moving further from the speaker is impractical (e.g. sitting next to a friend on the bus when his optimum distance for viewing is 4 feet). The child should be allowed to shift to (tactual) tracking when he chooses. In some instances, this technique will need to be taught to the child.

11) Does the child initiate or benefit from tactual signing?

Note: This is an abbreviated discussion of the important issues involved with tactual signing. Tactual signing, a receptive skill, should not be confused with coactive signing which is used to teach expressive signing.

Tactual signing is used by a person who understands sign language but cannot read signs and fingerspelling visually. To receive information, "the deaf-blind person places one or both hands on the hand(s) of the signer in order to read signs and fingerspelling through the tactual sense. (It is) ...a direct adaptation of a communication system originally intended for the tactual sense." (Reed, et al 1995.) Using tactual signing is a receptive skill.

Tactual signing is typically used with the student who is blind. For students who learn signs visually and then undergo a significant vision loss, there will be a process of relearning the signs tactually. Signs feel different than they look. There also may be emotional issues to face in switching to tactual sign because it is an admission of vision loss. This is an extremely stressful change for a person who is hard of hearing or deaf.

In order to be a skilled reader of tactual signs a person must do more than just learn how the signs feel. He will need to learn how to place his hands to get the most information without interfering with the speaker's ability to sign. Typically, the student uses both hands in the beginning. As his skills increase or if he is very familiar with his partner, he may use only one hand. The student will need to "keep it light" in terms of how much weight he puts on the hands of the person who is signing to him. The partner can fatigue very quickly, and over time, injuries like Carpal Tunnel Syndrome can occur if adequate breaks are not allowed. The person with deaf-blindness may also become fatigued because holding his hands in place for long periods of time is tiring, and reading signs tactually takes a great deal of concentration.

Much of the information conveyed in sign language is expressed through facial expressions, eye gaze, a slight shrug, etc. With tactile signing, every attempt should be made to find alternate ways to convey the meaning tactually.

When conversing with or interpreting for a person who is deaf-blind, additional environmental information should be supplied along with the conversation or lecture. For example, who is in the room, a description of the furnishings, an unexpected noise, etc. Without this information some comments may not make sense if people are referring to things that the deaf-blind person cannot see or hear. Have each person say their name before making a comment and provide the interpreter with a seating chart which contains the names of the others in the group.

While tactual signing is used by individuals whose vision loss is total, it is also used by people who have vision but are not able to see the signs and fingerspelling clearly enough to understand them. If a student with low vision initiates this modification, it should be respected as an attempt to gain necessary information. The child should be given the opportunity to receive signs tactually. Some students may need to use tactual signing in some situations and not in others. For example, a student may need to rely on tactual signs in very dim light, but be able to get by without it under good lighting conditions.

In some instances, utilizing tactual signing can allow a child to follow a discussion with his hands while he uses his vision to regard the item or situation under discussion. He doesn't have to choose what to look at. When a child becomes more sophisticated in signing, having to read longer sentences, he may no longer be able to get by on his vision alone. He may move to tactual signing because of a change in the level of demand upon vision. In another student, self-initiation of tactual signing could indicate a problem with the child's vision.

Using tactual signing will affect the pacing and design of the lesson. For example, if there are materials used in conjunction with the lesson, the child must have time to examine the materials before he can return his hands to his partner. If a teacher is signing to other students, it will be difficult for her to stop and repeat everything she says tactually to the deaf-blind student. She must also convey any comments that the other students make as well as reading information from the board or overhead. Almost without exception an additional staff member will be needed to provide tactual support.

12) If a student will benefit from braille, are there English acquisition issues associated with students who are deaf or hard of
hearing which should be addressed?

When determining whether print or braille should be used for a student who is deaf or hard of hearing, teachers will need to keep in mind that slow reading rates and problems with comprehension may be due to a difficulty in acquiring the English language. In many ways, these students' learning needs are similar to those students who are learning English as a second language. A change in literacy medium from print to braille may not improve reading performance for students experiencing language problems.

Techniques that might address this concern:

13) Are there instructional strategies, materials, and tools typically used with students who are deaf or hard of hearing which may present problems for the students with deaf-blindness?
  14) Are there modifications to standard interpreting arrangements or signed classroom instruction which need to be addressed?
Note: this is an abbreviated discussion of the important issues involved with appropriate interpreter services.

It is possible that a person with deaf-blindness may need a completely different interpreting arrangement than other hearing impaired students in the same classroom. Even in an environment where everyone is signing, you may need additional support. For example, at a recent conference we had four participants who requested sign language interpretation. One of the participants could see the platform interpreter who stood by the speaker. Two of the participants required a tactile interpreter. The fourth person used a close vision interpreter. Three different interpreting arrangements were needed simultaneously, in order to make the information accessible to all participants.

Adaptations about interpreter arrangements:

Tactual Interpreting (see question #11 )

Making the appropriate modifications and adaptations for a child with deaf-blindness is critical to their educational achievement. If his unique needs are not met, the child, no matter where he is placed, is in the most restrictive environment. He is cut off from any opportunity to learn. Unfortunately, these supports are not always easy or inexpensive to provide.

By conducting a thorough assessment of the childís visual functioning in accessing manual forms of communication you can determine the supports that are necessary. This will help you and your team to develop the type of programming which has the most benefit for the child educationally and make that program accessible to him.

Baker, Charlotte and Cokely, Dennis (1988). American Sign Language: a teacherís resource text on grammar and culture. Silver Springs, MD: T. J. Publishers.

Gustason, Gerilee and Zawolkow, Esther (1993). Signing Exact English. Los Alamitos, CA: Modern Signs Press, Inc.

Humphries, Tom; Padden, Carol; and OíRourke, Terrence J. (1980). A Basic Course in American Sign Language. Silver Springs, MD: T. J. Publishers, Inc.

Reed, Charlotte M.; Delhorne, Lorraine A.; and Durlach, Nathaniel I. (1995). A study of the tactual reception of sign language. Journal of Speech and Hearing Research, Vol. 38, 477-489, April 1995.

Watkins, Susan and Clark, Thomas P. (1991). A coactive sign system for children who are dual sensory impaired. American Annals of the Deaf, Vol. 136, No.4, pages 321-324.

This document is from the Texas School for the Blind and Visually Impaired.

A-Z to Deafblindness