The Dr. Bill Takeshita Foundation

Last Modified: Sat, 18 Aug 2007

View other Common Causes of Vision Impairment

Achromatopsia, also known as Rod monochromatism, is a congenital condition that affects the cone cells of the retina, causing blurred distance site, severe sensitivity to glare and bright light, and nystagmus, the horizontal shaking of the eyes. Achromatopsia is a genetic condition that is inherited at birth. It is generally a stable condition and there are no medical treatments to correct this condition.

The retina is the light sensitive tissue inside the eye. The retina is made up of two different types of cells that receive light and convert light energy into electrical energy. The rod cells are located on the periphery of the retina and are responsible for peripheral (side) vision, night vision, and the perception of motion. The cone cells are located in the center of the retina and provide detailed sight, color vision, and the cone cells also control light sensitivity Children born with Achromatopsia do not have cone cells and thus they have symptoms of blurred sight, color blindness, and photophobia. Generally, children with adults with Achromatopsia have visual acuity of 20/200 and are totally color blind. However, there are some cases in which there are some cone cells present and these patients may have sight better than 20/200 and they may be able to perceive some colors.

Children and adults with achromatopsia respond extremely well to low vision rehabilitation. Low vision doctors are able to design specialized classes and contact lenses to reduce their sensitivity to glare and bright light. Special colored filters can also help people with achromatopsia to perceive colors somewhat better while optical low vision aids and glasses can improve their clarity of sight.

Recommendations

• Position students in the front portion of the classroom such that their backs face Windows, doors, and sources of glare
• Provide students with copies of handouts in large print format. 20-point type size with Arial font is very helpful.
• Students will benefit from having copies of materials that are presented on the board or on overhead projections.
• When possible, reduce the ambient room illumination. Students will benefit from having a dark poster board placed on their desks to reduce reflective glare. Also, tinted paper can be very helpful.
• For more information, please see Low Vision Rehabilitation