Small Pupil Size For Better Visual Acuity.

~Dilated (wide) pupils allow abberant rays to scatter across the retina, which hinders
clear vision.

~Small pupils focus an image rather than scatter it.

~Small pupils increase depth of field.

~Pupil size is controlled by strength and presence of a specific frequency of light.

~The Skylighter's unique spectrum can artificially reduce pupil size at typical indoor light levels, resulting in improved acuity.

Cones are "day vision" or "color vision" cells.

They are most sensitive to green-yellow light at 550 nanometers, referred to as photopic energy. Green-yellow is the color we see best during the day.

Rods:  The "night vision" cells.

The super-sensitive rods allow us to see at almost-dark conditions.  Rods are most sensitive to blue-green light , referred to as scotopic energy..

Rods: New insight.

Until recently it was believed that "night vision" rods were inactive in lighted conditions.

It turns out that  "night vision" rods are always at work.
Rods have great control over pupil management.