Achromatopsia, the visual impairment that Wilmette teen Meirav Malter and her sister Ma’ayan were born with, is a rare disorder in which humans lack the use of important photoreceptors in their eyes.
Human eyes have two separate types of light receptors; cone-shaped ones that allow us to see sharply, in color, and in bright light, and rod-shaped receptors that let us see in low light, but which don’t transmit sharp or color images.
People with achromatopsia have malfunctioning or missing cone receptors. They have poor visual acuity, paired with complete or near-complete color blindness and a painful inability to see in daylight or indoor illumination without heavily filtered lenses, most often filtered to let in only red light. The more light they must deal with, the less they can see, and the more painful it is to try.
A very rare form of the disorder, called blue-cone achromatopsia, lets those with it see some colors.
The disorder affects one in every 33,000 people in the U.S., depending on the version; that number ranges higher, up to 50,000, with rarer versions of achromatopsia, and also varies throughout the world.
Achromatopsia is congenital, stable and non-progressive – people are born with achromatopsia, but won’t eventually lose all their vision – but there is no cure for it yet, although there have been some promising trials in animal experiments.
To learn more about achromatopsia, you can visit www.achromat.org/, http://www.achromatopsia.info/ or www.aapos.org/terms/conditions/10.Tags: Meirav Malter