The influence of assistive technology devices on the performance of activities by visually impaired

Objective: To establish the influence of assistive technology devices (ATDs) on the performance of activities by visually impaired schoolchildren in the resource room. Methods: A qualitative study that comprised observation and an educational intervention in the resource room. The study population comprised six visually impaired schoolchildren aged 12 to 14 years old. The participants were subjected to an eye examination, prescribed ATDs comprising optical and non-optical devices, and provided an orientation on the use of computers. The participants were assessed based on eye/object distance, font size, and time to read a computer screen and printed text. Results: The ophthalmological conditions included corneal opacity, retinochoroiditis, retinopathy of prematurity, aniridia, and congenital cataracts. Far visual acuity varied from 20/200 to 20/800 and near visual acuity from 0.8 to 6 M. Telescopes, spherical lenses, and support magnifying glasses were prescribed. Three out of five participants with low vision after intervention could decrease the font size on the screen computer, and most participants (83.3%) reduced their reading time at the second observation session. Relative to the printed text, all the participants with low vision were able to read text written in smaller font sizes and reduced their reading time at the second observation session. Conclusion: Reading skills improved after the use of ATDs, which allowed the participants to perform their school tasks equally to their classmates.


A
ccording to the World Health Organization (WHO), the levels of disability associated with visual impairment range from low vision to blindness (1) .The 10 th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) defines low or subnormal vision as a visual acuity of less than 0.3 and equal to or greater than 0.05 in the eye with the best corrected vision or a visual field of less than 20 degrees (categories 1 and 2 of vision impairment).Blindness is defined as a visual acuity of less than 0.05 or a visual field of less than 10 degrees (categories 3, 4, and 5 of vision impairment).An undetermined or unspecified loss of vision corresponds to category 9.This classification is based on the 9 th revision of the ICD with the classification in the ICD-10 as a reference (2) .
The following visual functions might be affected in individuals with low vision: visual acuity, visual field, an adaptation to light and dark, and color perception.The visual function of individuals with low vision might be improved with assistive technology devices (ATDs).
Assistive technology is an interdisciplinary field of studies that encompasses products, resources, methods, strategies, practices, and services to enhance the functional capability related with the activity and participation of people with deficiencies, disabilities, or reduced mobility to improve their autonomy, independence, quality of life, and social inclusion (3) .
ATDs are potentially beneficial for schoolchildren with low vision and are classified as optical, non-optical, electronic, or computer-based.Computer-based resources for blind individuals include refreshable Braille displays and software replacing images with voice (voice synthesizers) (4,5) .
Schoolchildren with low vision might exhibit difficulties in reading and writing even while using optical and non-optical aids.For such schoolchildren, computer-based devices might not only be helpful in school assignments but also as pedagogical instruments that facilitate the insertion of computers in social and educational practices, thus becoming relevant for the academic development of such children (6) .
It is important to convey the benefits associated with ATDs among schoolteachers to improve visually impaired students' access to special education within the context of a partnership between the education and healthcare fields to provide global interventions for the visually impaired (7,8) .
The aim of the present study was to investigate the influence of ATDs on the performance of school tasks by visually impaired schoolchildren as a function of the relevance of the educational conditions necessary for the development of individuals with low vision.

METHODS
The present qualitative study included observations of schoolchildren in their natural environment, and an educational intervention was performed in a resource room for the visually impaired.
The study population comprised six schoolchildren, five with low vision, and one blind, from 12 to 14 years old.The children attended a public elementary school in the municipality of Santa Barbara do Oeste, São Paulo state, Brazil and were users of the resource room for the visually impaired.
The participants were subjected to a full eye examination by eye doctors from the Subnormal Vision Service, Clinical Hospital of the School of Medical Sciences, State University of Campinas (Serviço de Visão Subnormal do Hospital das Clínicas da Faculdade de Ciências Médicas da Universidade Estadual de Campinas -SVSN/HC/FCM/UNICAMP).Optical and non-optical aids were prescribed to the participants on an individual basis.
The study was approved by the Research Ethics Committee of the School of Medical Sciences of the State University of Campinas under ruling no.421/2003.
The participants and their guardians signed an informed consent form following an explanation of the study aims.

Procedures
During the initial observation session in the natural environment setting, the participants performed school assignments in the resource room.For the tasks that involved reading on a computer screen and from a printed text, the researcher provided a simply written text (Text 1) and assessed the following: 1 -the eye-object distance relative to the computer screen, font size, and time required to read; 2 -the eye-object distance relative to the sheet of paper (printed text), font size, and time required to read.

Text 1
"The boy and the man: When I was a child and it rained, our home became a leak festival.The ceiling dripped and soaked the floor of all the rooms and halls.We'd all get crazy, running here and there with pails, bowls, pots, and potties" (9) .
An educational intervention was then performed.This intervention consisted of a course on the use of accessibility software for the visually impaired taught by a teacher with computer specialization.
The 144-hour course was taught over eight months and comprised the simultaneous use of the accessibility assistant software included in the computer and sound or magnification software (Dosvox or Virtual Vision).
During the final session of observation assessing the participants' performance, reading and typing activities (Text 2) were performed using optical, non-optical, and computer-based devices.The text was selected based on the participants' academic level.The parameters assessed were identical to those utilized in the initial observation session: 1 -the eye-object distance relative to the computer screen, font size, and time required to read; 2 -the eye-object distance relative to the sheet of paper (printed text), font size, and time required to read.

RESULTS
The data relative to the eye examination and device prescription are described in table 1.
The data collected during the observation sessions before and after intervention are comparatively described in tables 2 and 3.
Table 2 shows the reduction of the time required to type and read on the screen.For participants 2 and 5, the teacher chose to increase the font size at the second observation to improve their body posture and achieve better visual performance.
Table 3 shows that the reading time also decreased relative to the printed text.A comparison of tables 2 and 3 shows that the reading time on the computer screen was similar or longer than that corresponding to the printed text.

Table 1
The cause of vision impairment, corrected visual acuity, and optical and additional devices prescribed to the visually impaired schoolchildren (SVSN/HC/FCM/UNICAMP) Text 2 "What is love?Two teachers taught the fourth grade.One was young and inexperienced.The other was a woman in her sixties, and had an advantage of 40 years of brilliant performance reviews that made her be known as a good teacher" (10) .

DISCUSSION
The present study included an adaptation of the ATDs so reading and writing could be performed simultaneously.The optical and computer-based devices were mutually adjusted, thus resulting in shorter reading times.The adjustment of the prescribed optical and non-optical aids was relevant for the results observed.
The schoolchildren interviewed in a study conducted at State University of Campinas (Unicamp) reported that when optical,