It is a try to show the miraculous combination/adjustment of sun, eyes and atmosphere in visible range of electromagnetic spectrum

1. Color Vision
The human visual system can detect the range of light
spectrum from about 400 nanometers (violet) to about 700
nanometers (red). Our visual system perceives this range of
light wave frequencies as a smoothly varying rainbow of
colors. We call this range of light frequencies the visual
spectrum.
Photopic vision is the vision of the eye under well-lit
conditions. In humans and many animals, photopic vision
allows color perception, mediated by cone cells.
The human eye uses three types of cones to sense light in
three respective bands of color. The biological pigments of
the cones have maximum absorption values at wavelengths of
about 420 nm (blue), 534 nm (Bluish-Green), resp. 564 nm
(Yellowish-Green). Their sensitivity ranges overlap to provide
vision throughout the visible spectrum. The maximum
efficacy is 683 lumens/W at a wavelength of 555 nm (green).
Left side is a graph of The 1931 CIE photopic luminosity
function. The horizontal axis is wavelength in nm
Courtesy: Wikipedia
Eye
Congenial company of Sun, Eye
and Atmosphere for Visible Range
of electromagnetic spectrum in
Nature
Miraculous combination of Sun-Eye-
Atmosphere in visible range of
spectrum i.e. 0.40 to 0.70 μ m
is like Darwin's theory being applied
to Sun-Eye-Atmosphere .
What will happen if this coincidence
get disturbed?
Will our eyes modify as per new
situations in future?
Can we describe some historical
events like ice age, extinction of
many species of plants and animals
in light of this combination
disturbance?
As the temperature decreases, the peak of the black-body
radiation curve moves to lower intensities and longer
wavelengths.
Sun Atmosphere
The spectrum of solar radiation (at the top of the
atmosphere) and a blackbody with T=6000 K. In visible range how generously Sun is sending radiations, earth is
Wien's Law: receiving these radiations in this range without atmospheric In visible range most of the radiation is transmitted towards the earth
The wavelength of maximum brightness is inversely
proportional to the gas temperature hindrance and our nerves of eyes are also well adapted for this without much absorption
or, wmax = (a conversion constant) / T range . How brilliant combination of nature! How long??
The peak of sun’s energy is falling on 0.5 μm and in visible
range we are getting most of the sun’s energy (40%).
As a consequence of Wien's displacement Law this
situation is not constant. The peak will shift to the longer
wavelengths side and total energy will also reduce as per Courtesy: Pictures/graphs and text are mostly downloaded from Wikipedia
Stefan’s Law as the sun’s temperature will reduce in future