
1.2 Vision 11
yetdevelopments in this area are forthcoming. The fact that rods are more sensi-
tive to low-light environ ments, that scotopic vision shifts to shorter wavelengths,
and that rod concentration increases in the periphery of the retina mean that rods
and peripheral vision are more sensitive to blue light.
Adaptation is the mechanism by which the eye changes its sensitivity to light
and can take place by adjusting the iris and pupil size, the nerve endings in the
retina, or the chemical compositions of the photopigments in rods and cones.
The human eye can function from very dark to very bright levels of light; its
sensing capabilities ...