Autistic Spectrum

People on the autistic spectrum are considered to have a ‘neurodevelopmental condition’ which can be characterised by issues with communication, social awareness and the presence of repetitive, stereotypical behaviours. These repetitive behaviours can include ‘rocking’, ‘hand-flapping’ and tapping their own body with their hands otherwise known as ‘stimming’.

People on the spectrum may also avoid eye contact and avoid unfamiliar places and situations. They may also show fascination with movement and/or fascination with a particular interest.

They may also display ‘toe walking’ or may bang their feet heavily on the floor as they walk.

They may easily knock things over when they are reaching for them or miss them completely.

They may have issues walking up and down stairs or maintaining their balance on uneven surfaces.

They may also go into ‘meltdown’ in certain situations where they seem to get too much stimulation.

They may show hyperactive and inattentive behaviour and have an unusual posture.

They may also have issues recognising people’s faces and show hypersensitivity in certain senses such as touch, hearing, taste or smell.

An optometrist in America, Melvin Kaplan hypothesised that people on the autistic spectrum have a subtle visual dysfunction that causes their symptoms and behaviours.

Whereas people commonly think of vision as just being able to read letters from a chart, Kaplan felt that other visual factors were also contributing to the behaviours seen in patients on the spectrum.

Kaplan proposed that the peripheral vision in such patients was not working in synchrony with their central vision.

So, for instance when you walk around, your peripheral vision hopefully remains stable. Kaplan proposed that for somebody on the spectrum their peripheral vision was not stable and as one person on the spectrum put it, ‘…when I walk around it is like I am surrounded by walls of jelly that are moving around and wobbling around me…’

When you have a communication problem, it is challenging to put these effects into words.

Kaplan did studies prescribing ‘yoked prism glasses’ to patients and the wearing of these glasses reduced or relieved their symptoms, stopped these behaviours and improved their function.

As a result, life was much easier for these patients.

‘Prism’ is something that is commonly used by optometrists to improve the eye coordination of patients with eyestrain or occasional double vision. Such prism is usually prescribed in one or both eyes.

If prescribed in both eyes the prism in prescribed in opposite directions so encouraging the eyes to work together better.

The prism which Kaplan prescribed is ‘yoked prism’ where the prisms are prescribed in the same direction in each eye.

Now this might seem to not make any difference because all you are doing is effectively moving your field of vision either upward, downward, to the right or to the left.

However, Kaplan found that when prescribing the appropriate amount of yoked prism to people on the autistic spectrum that in a variety of cases these patients stopped ‘stimming’, walked normally, could walk up and down stairs which they could not do before, could run without falling over and could recognise faces.

So why has this approach not become more popular?

Well, Kaplan did not do many studies and did not do his studies on large enough groups of patients to make his results statistically significant.

Also, in the case of prescribing yoked prism to patients on the autistic spectrum we do not know how yoked prisms work though it would be interesting to find out.

Kaplan also stated that he felt that the beneficial effect produced by the yoked prism glasses could well be temporary and that a vision training programme was best followed in conjunction with the wearing of the prism glasses to ensure establishment of these new visual skills.

Personally, I have fitted yoked prism glasses to patients on the spectrum and in the one case the patient could walk up and down stairs for the first time, in fact run up and down stairs for the first time.

In another case they could run up and down stairs, run across the room to their parents and recognise people’s faces for the first time.

Laypeople and optometrists are encouraged to read the book ‘Seeing Through New Eyes’ by Melvin Kaplan.

For the scientists out there, there are one or two studies which showed success when vision training and prism glasses were used together with such patients though you will find that the patient sample was relatively small.