most of the cones are located in the retina of the eye.
most of the cones are located in the retina of the eye.
where are most of the cones located in the eye?
retina
in details, the normal human eye contains three different types of cones, with different ranges of spectral sensitivity. the brain combines the signals from neighboring cones to distinguish different colors. there is only one type of rod, but the rods are more sensitive than the cones, so in dim light they are the dominant photoreceptors active, and without information provided by the separate spectral sensitivity of the cones it is impossible to discriminate colors. in the fovea "centralis", cones predominate, and are present at high density. the macula is thus responsible for the central, high-resolution, color vision that is possible in good light; and this kind of vision is impaired if the macula is damaged, for example in macular degeneration.
macula of retina
the sixmile butte lava field, of pleistocene age, consists of ten cinder cones between black butte and black crater. these cones erupted basaltic andesite, which was deposited prior to the glacial advance at suttle lake. the field encompasses about . lava deposits from nearby cache mountain have a normal magnetic polarity, corresponding to an potassium–argon dating age of 0.9 ± 0.05 million years, suggesting they were produced during the jaramillo normal polarity of the matuyama period between 0.98 and 1.04 million years ago. there is a chain of pleistocene cinder cones east of the butte that trends from northwest to southeast, with other pleistocene cinder cones located to the south. there is also a mafic, well-preserved cinder cone above the green ridge fault zone, which produced a pleistocene lava flow.
black butte (oregon)