It measures the oceans depth!
PROTANOPE. These are the individuals that suffers form color blindness. This color blindness is due to the absence fo the L- cones which are cones that are sensitive to long wavelength. Cones are one of the three types of photoreceptos found in the retina. These are responsilble for color vision and function best in a brightl light. In contrast to the rods which works on dim light. Cones are found in the fovea.
It is the presence of oxygen-bound hemoglobin that makes it bright red
