|Patients with color vision deficiency have another option when it comes to improving color contrast.
High school student Vladimir Mamchik recently created a user-friendly, noninvasive solution to improve color contrast and produce differential dynamic illumination for those with color vision deficiency, which affects over 500 million individuals worldwide.
The study created illumination by combining light produced by a set of color LEDs. Initially, several candidate LED-based illumination sources were characterized for spectral composition and responsiveness. Then, low-cost microcontrollers were evaluated based on their performance and ability to interface with peripheral devices. With the selected light source and microcontroller, a hand-held illumination system, which included an integrated user interface in a compact 3D-printed casing, was developed. It is controlled by a program, written in Python, which allows for full control of illumination parameters, including luminosity, spectral composition and temporal frequency.
“This system is based on previous research, which identified an effect that allows color vision-deficient observers to perceive color contrast when a specific illumination condition is applied (differential dynamic illumination),” Mr. Mamchik said. “By dynamically changing the spectral composition of the illuminating light at high frequencies, a brightness contrast is introduced between previously indistinguishable colors.”
Two of the three study participants had deuteranopia, a severe color vision deficiency. The third subject had normal color vision, acting as a control. Tests were conducted by asking subjects to identify numbers on standard Ishihara Test Plates, and light pulses of white, magenta and cyan were alternated, the frequency of which was controlled by pulse length/time delay.
For the first subject, the color contrast recognition rate at 16.26Hz increased by 78%, and for the second subject, the color contrast recognition rate at the same frequency increased by 48%, while at 13Hz, it increased by 72%. The color contrast recognition rate for the subject with normal color vision remained at 100% for all illumination conditions.
The study gave way to an innovative microcontroller-driven device, providing a noninvasive correction method for those with color vision deficiency and allowing them to detect previously indistinguishable colors at a comparable or the same rate as observers with normal color vision.
“The created device allows the researcher or general user to control illumination, frequency and spectral composition to all necessary specifications with greater efficiency than previous devices,” Mr. Mamchik concluded.
Mamchik V. Novel microcontroller-driven illumination system to improve color contrast recognition in observers with moderate to severe color vision deficiency. AAO Meeting 2021.