mesopic vision

Since these cells respond mostly to blue light, it has been suggested that they have a role in mesopic vision.

Mesopic vision occurs between these limits and is not well characterised for spectral response.

Mesopic vision falls between these two extremes.

The human eye uses scotopic vision under low-light conditions, and mesopic vision in intermediate conditions.

Between these regions, mesopic vision comes into play and both rods and cones provide signals to the retinal ganglion cells.

Mesopic vision is a combination of photopic vision and scotopic vision in low but not quite dark lighting situations.

When light levels are low enough for both rods and cone cells to be active (mesopic vision) the enhanced rod activity induces the bluish visual tint.

Mesopic vision occurs in intermediate lighting conditions (luminance level 10 to 1 cd/m2) and is effectively a combination of scotopic and photopic vision.

It is also theoretically possible to incorporate rod cells, which optimally perform at a dark cyan color, in well-optimized mesopic vision, to create a fourth filter color and yet another perspective; however, this has not yet been demonstrated, nor would most televisions be able to process such tetrachromatic filtering.