The retina turns light into signals. Rods and cones do different jobs, and the order in which they are affected explains some condition names.
Look for fine detail on the shelves and the larger shapes around the door. Your screen shows an illustration. This cannot test your night vision or reproduce dark adaptation.
Room illustration hidden. The explanation below still applies.
Cones work best in brighter light. They are packed into the centre of the retina, especially the fovea, and they handle detailed central vision and colour. Rods and cones are not an on-off switch. Their contributions change with the lighting.
In many forms of retinitis pigmentosa, rod function changes before cone function. Trouble in dim light and changes to side vision often come before problems with central detail. The pattern and the pace vary.
Read about retinitis pigmentosaCone-rod dystrophy usually affects cone function first. Central detail, colour and comfort in bright light change early. Rod involvement can later affect dim-light and side vision.
Read about cone-rod dystrophy