Warped placements of the green and red cones makes a person colourblind. As a result, 1 colour is replaced by black enhancing the brightness of the other. Scientists at Aston University in the English Midlands are using this as a basis for developing the first test to detect colourblindness in 1-day old infants.

Lead researcher Professor Graham Harding explains that until they are 6-8 weeks old, babies cannot see colours. But they can differentiate between pattern changes. Shown a pattern of green and red of equal brightness, a day-old colourblind baby will react to the vision as, 1 colour appears brighter, and the other black.