Question

one common treatment for congenital chromatopsia or rod monochromatism is for the individual to wear red/brown contact lenses or glasses? why is this helpful?

Answer 1

Congenital chromatopsia is an inherited disease characterized by color blindness. In the human eye in the retina, there are millions of rods and cones at the rear of the eyes. Rods and Cones are the photoreceptors. Rods are responsible for the scotopic vision and have a low spatial acuity, they do not mediate color vision. The Cones are responsible for the photopic vision of high spatial acuity. Cones are present in the central fovea region of the retina.

Rods are active at low light levels and Cones are active at higher light levels there are approximately 150,000 cones/ sq. mm. There are three types of Cones acts at different light wavelengths.

The people who lack Cone photoreceptors suffer from Congenital chromatopsia as we know the Cones are active at higher levels with the absence of Cones their eyes do not adapt to the high or illuminated lights they are photophobic. In high illuminated light the vision decreases they have to blink or squint to reduce the light entering the eyes.

The patients who suffer from chromatopsia can work comfortably in the dim light but in an illuminated light or outside in a sunny day it is difficult to adjust to the bright light.

With the use of red central contact lenses, the amount of light entering the eye gets adjusted to the illuminated or outdoor light. The centrally tinted contact lenses reduce photophobia by decreasing light sensitivity that helps in improve visual acuity.