Introduction to Assistive Technology for Vision Impairments

Module 3: Assistive Technologies for People with Vision Impairment for various life domains

3.1 Introduction

Assistive Technology is a continuously changing and dynamic field, especially in relation to advancements in technology and emerging needs. The benefits of an assistive product depends on various factors that determine if the product is a good match to fulfil the goals and needs of the person using it and if the services for training, customization, repair and maintenance of the product are available.

Assistive technologies have greatly improved the quality of lives of persons with vision impairment, across different domains such as literacy, computer access, mobility and activities of daily living. Let us first look at how assistive devices used by persons with low vision may differ from those used by persons with complete loss of vision.

In this video, Dr. Anuradha from Sankara Nethralaya, highlights the existing assistive devices and the gap areas which require more focus.

About Resource Person

Focus Areas covered:

Assistive technologies for persons with visual impairments in different domains like:
  • Orientation and mobility
  • Activities of daily living 
  • Access to literacy 
  • Access to digital content.
Reading Material for Above Lecture

Key differences between augmenting vs replacing the visual sensory pathway
As we’ve seen earlier, Persons with Vision Impairment include Persons with low vision and People who are completely blind. The approach towards assessing vision as well as prescribing AT can be very different for persons with low vision, as compared to those who are completely blind.
For people with low vision, the primary pathway for vision exists and can be augmented. For example, the limitation could be in the:


    1. Intensity of the input signal – In this case, magnification aids (optical, non-optical, electronic) may be used as a solution.
    2. Frequency or wavelength – Color contrasts or filters may be used by users
      with this limitation.
    3. Field limitation – Lenses that widen the field are commonly used to solve this issue.

When the visual sensory system is completely impaired, it must be substituted by an alternative sensory pathway, such as the tactile (touch) (Eg: Braille) or the auditory (Eg:  Screen reader) modality.

Video- 10mins