Birmingham researchers develop contact lens to correct colour blindness

Scientists combine inexpensive soft contact lenses and non-toxic rhodamine derivative dye to improve red-green colour vision

Colour blind eye image

University of Birmingham researchers have reported that contact lenses tinted with a rhodamine derivative dye can help people with deficiencies in their red-green colour vision.

The research team highlighted that while there are already glasses with colour filters capable of correcting colour blindness, this solution can be expensive and bulky.

As part of work described in Advanced Healthcare Materials, scientists used a non-toxic dye derived from rhodamine to stain inexpensive soft commercial contact lenses.

The dye is known for its ability to absorb certain wavelengths of light in the optical spectrum.

Researchers found that the dye blocks the band that lies between the red and green wavelengths, enabling better differentiation between red and green colours.

The researchers tested the effectiveness of the lens by attaching it to a glass slide. People with red-green colour vision deficiency then looked through the lens at their surroundings and a series of numbers.

The study participants were then asked if they noticed any improvement in their colour perception, with the group reporting positive results.

Lead researcher, Dr Haider Butt, highlighted that the dye used in the experiment is not toxic to the human eye and the method can be used in both contact lenses and spectacles at a low cost. Human trials are scheduled to begin shortly.

“We are now looking into a similar process to correct purple-blue colour blindness, and also to bring together a number of dyes to make lenses perform for both red-green and purple-blue colour blindness simultaneously,” he shared.

Image credit: University of Birmingham