Genetic phenomenon- congenital hereditary. Incidence of the disease 1:40,000 births.
The retina is the part of the eye that catches the light. It consists of two types of receptors, which are the cells that correspond to light and convert the image into electrical images that pass to the brain.
There are 2 types of receptors: 1. Rods 2. Cones.
- Cones are responsible for seeing details, colors, central vision and day vision.
- The nests are responsible for peripheral vision and night vision.
The disease damages the two systems together, when first there will be damage to the cones ( Cones and therefore less good visual acuity, there will be impairment of color vision and hypersensitivity to light. After that, rods will also be damaged and night vision difficulties and many mobility difficulties will develop due to loss of peripheral vision.
Implications for functioning:
The disease does not have preventive treatment or cure although less exposure to light may slow the rate of development of the disease. Blunt glasses that help due to light sensitivity are essential and it is also important to emphasize mobility education from an early age (when there is still peripheral vision). Due to the damage from central vision it is necessary to work with enlargements and utilities, allowing the child to approach objects (this causes enlargement and then it is easier to identify them) and not rely on colors. When age and intellectual level allow, children with optical devices should be helped to have vision.
*A similar/parallel disease is Rod-Cone Dystrophy when the difference is that this is where the injury begins in the system of the nests and only after that the cone vision is impaired.