Visual Stress

Diagrams of the brain are overly simple. They show one function here, another function there, and no interaction between them. The reality is complex. Neurons fire more like shotguns than rifles, so neuronal activity spreads broadly. To one extent or another, different parts of the brain commonly interact.

One such interaction is between areas perceiving colour and areas perceiving lines or flicker. These interactions can affect reading. Unfortunately, this is a topic that has seen extravagant claims, sloppy research, and scientific interest damped by patents in North America. However, some good research has come out of the UK, primarily by Arnold Wilkins. Wilkins has shown convincingly that real interactions do exist, and these interactions affect a significant minority of the population. Little else is known for sure but:

To see if you may be helped by a tinted screen, I created this one-minute test using colours that Wilkins suggested. It is a rough electronic equivalent of a test he developed using transparent plastic overlays. Click through its different colours. Most likely you’ll see no difference from one to another, but if a colour makes the text more or less stable or more or less clear, then you might generally from tinted eyeglasses, especially if you get migraines from time to time or occasionally get epileptic fits.

In the UK, many opticians prescribe and dispense tinted lenses inexpensively under the National Health Service, based on scientifically proven technology that Wilkins developed at Cambridge University. Outside the UK this technology is available sparsely, although a sales force set up by Helen Irlen is ubiquitous in North America. Irlen's lenses can be effective, but her methods of determining the optimal tint are imprecise. Here are links to Wilkins's system and Irlen's.

Here is an academic review of this subject by Wilkins.

—Charles Maurer