These simple-looking glasses hold a secret power: they allow people with red-green colour blindness to experience colours which they would normally be unable to see.
Level 3, Technology by Design, National Museum of Scotland
Did you know
Dr Don McPherson, the cofounder of Enchroma, discovered the glasses when he was working on lab glasses for protection from laser eye surgery.
Colour blindness is a condition where a person is unable to see certain colours under normal light. It affects millions of people worldwide and about 2.7 million people in the UK alone.
Colour blindness (or colour vision deficiency) mainly affect men with 1 in 12 men affected and only 1 in 200 women. It can be caused as a result from certain diseases (such as diabetes or multiple sclerosis), but most people have inherited it genetically. People with colour blindness are not usually blind to all colours and the specific colours that they can see depends on the type of colour blindness that they have.
Holmgren's wool, colour blindness test in which the subject matches various coloured skeins of wool, with instructions, used at the Royal (Dick) School of Veterinary Studies, University of Edinburgh, devised by Alarik Frithiof Holmgren.
People with full colour vision can see an enormous range of different colours. Every colour in the spectrum is a unique wavelength of light. Our eyes don’t have unique detectors for every single colour, instead we have only three different colour detectors – red, green, and blue. These three colour detectors in our eyes, allow us to see all the colours that make up the visible spectrum of light. This works in a similar way to how we can make yellow paint by mixing blue and green together. The colours that we perceive are really just combinations of red, green, and blue. Computers and televisions take advantage of this by using just these three colours to generate every shade that you see on the screen.
“When you see something yellow on the screen, it is not really yellow. It is just a unique combination of red, green, and blue that has been mixed together.
Red-green colour blindness is the most common type. This occurs because the red and green detectors overlap more than normal, which means that certain colours are not being detected. However, this doesn’t just mean that only red and green are mixed up, it also means that they can confuse all colours that have red and green in them. This of course includes loads of colours: oranges, pinks, purples, browns and even black!
These glasses made by Enchroma have tried to tackle the issue of red-green colour blindness with special filters built into the lenses. These special optical filters remove small slices of light where the red and green cones overlap the most in the eye of the colour blind. This re-establishes a more accurate ratio of light entering the three photopigments so the color blind enjoy a more normal spectral response.
These glasses have allowed people with colour blindness to experience enhanced colour, an improved ability to differentiate hues of colours, and better depth and detail perception.