Question

Optical and non-optical aids help visually challenged persons to develop their skills to a higher level in this way:

Optical aids: These include lenses and telescopic aids. While suitable lens combinations are used to rectify visual limitations, the telescopic aids can help to view class demonstrations and the blackboard.

Non-optical aids: These often include (1) tactual aids (using sense of touch; the visually impaired can learn to read and write by using a special touch system called the Braille. This system makes use of raised dots (put on a paper) and (ii) auditory (using sense of hearing) aids include audio cassettes, tape recorders, audio CDs, audio books. Other electronic devices (like computer/calculator/closed circuit television) make use of software programmes that can transfer ‘text files’ into sound.