Contact Lens For Red-Green Colour Blindness

Colour vision deficiency is an inherited ocular disorder in which some individuals have trouble distinguishing between certain colours. There is no known cure for the disorder currently available, but there are several methods that can be used to increase colour perception in the affected. Products on the market currently are bulky, expensive, and incompatible with other vision corrective glasses.

Trichromatic vision is normal vision that mean any colour or combination can be created and will be perceived by cluster of cones at the back of the eye which are divided into 3 groups: blue responsible for short wavelengths, green medium wavelengths, and red long wavelengths. The brain receives incorrect information when on of these cones are missing resulting in limited ability to identify certain colours.

Glasses and custom made lenses are available on the market for colour blindness correction, but they are expensive. Inexpensive soft commercial contact lens dyed with non-toxic rhodamine derivative dye were used to conduct this study that is known for the ability to absorb certain wavelengths of light within the optical spectrum; which was found to block the band laying between red and green wavelengths which is perceived by two corresponding optical cones simultaneously; removal of this band through dyed lens inhibited triggering of cones designated for red and green wavelength bands, which enabled better differentiation between the two colours.

Testing was conducted on participants with red-green colour vision deficiency as a stained glass slide, which included looking at several numbers through the lens and noted whether there were improvements to colours or clarity, and whether there was any improvements in their surroundings colour perception. Results of testing verified that the dye tinted lenses could be used to enhance colour perception for individuals affected by colour vision deficiency.

Contact lenses are of interest in this area because it is an easier way to correct the entire field of view that can be worn with other vision corrective glasses, that doesn’t require complex preparation, is non toxic, and is low cost.

Additional patient participant studies are currently underway to investigate a similar process for correcting purple-blue colour blindness, and to bring together dyes to make lenses which will perform correction for both purple-blue and red-green colour blindness simultaneously. Human clinical trial will be commencing soon.