Tenons

The cones in the retina are photoreceptors. They convey coloured points of light, which are put together by the brain to form an image. In contrast to the rods, they are unequally less, but instead more strongly represented in the area of best vision, i.e. directly opposite to the entrance of light through the lens.

https://de.wikipedia.org/wiki/Zapfen_(Eye) _{(Wikipedia CC-by-sa-3.0)}