For low vision specialists and those who consult them
Telescope training: is there evidence?
November 3, 2009Posted by on
At the moment there is lots of interest in implanted miniature telescopes for people with low vision (where the lens inside the eye is surgically replaced with a magnifying telescope). I will discuss these in another post, but this topic started me thinking about conventional, hand-held monocular telescopes, and the relative benefits of these.
In particular, I am interested in the role of training people to use these telescopes. There are three key things telescopes can be used for: spotting (“what is the name on this street sign?”); tracking (“what is the number on this moving bus?”); and scanning (“I know there is a sign somewhere near here, where is it?”).
Most people can probably manage to spot something with a telescope with practice and no training, as long as the principles of telescopes are explained to them (eg. you need to adjust the length of the tube to focus it; you need to make sure you’re standing still when you’re using it; you need to hold it as close to your eye as you can). However, more complex tasks such as tracking and scanning are difficult to perform without some guided practice or training.
In the UK, some local charities for the visually impaired perform this training, but there are still plenty of people who do not receive training and who just “pick up their telescope” and go home and use it. In the USA telescope training is commonly performed by rehabilitation workers, but there are still people with telescopes who have not received training.
Unless my quick literature search didn’t find it, it doesn’t seem that there has been a systematic study on telescope training to answer some key questions such as:
– what can people with low vision do with a telescope without training?
– how much training is needed to be able to perform certain tasks with a monocular telescope?
– how much better is performance with a telescope once training has been performed?
Once we have answers to questions like these, we can make a much stronger case to funding agencies that device training should be made available to more people. This would also make a nice project for someone looking to do a Masters or PhD in vision rehabilitation too.