the cones are concentrated in the fovea in the retina.
where are the cones concentrated in the retina?
the fovea
the central retina predominantly contains cones, while the peripheral retina predominantly contains rods. in total, there are about seven million cones and a hundred million rods. at the centre of the macula is the foveal pit where the cones are narrow and long, and, arranged in a hexagonal mosaic, the most dense. at the foveal pit the other retinal layers are displaced, before building up along the foveal slope until the rim of the fovea, or parafovea, is reached, which is the thickest portion of the retina. the macula has a yellow pigmentation, from screening pigments, and is known as the macula lutea. the area directly surrounding the fovea has the highest density of rods converging on single bipolar cells. since its cones have a much lesser convergence of signals, the fovea allows for the sharpest vision the eye can attain.
retina
the field consists of cinder cones and lava flows. the lavas cover a surface area of and tend to have thicknesses . many of these were erupted from fissures with no clear vents. cinder cones have average heights of above basis. there is some geographical differentiation with the largest cones found on the western side and the cones concentrated on the easternmost edge. a flat lava plateau also makes up the field. approximately 214 vents were counted in 2013. many of these vents are elongated in north-south direction, with a slight nnw-sse slant.
jaraguay volcanic field