Colour Science & Perception
what the eye settles, and what it cannot
Generator

The yellow screen that covers the fovea and nothing else

Macular pigment optical density against degrees from the centre of gaze, as an exponential of scale 2.4°. It peaks at 0.35 — this site's median observer's value, used unchanged — and is down to 0.005 by 10 degrees. A cone at the centre of gaze and a cone 10 degrees away are looking through different filters, so they have different colour-matching functions. They are in the same eye.
The yellow screen that covers the fovea and nothing else. Macular pigment optical density against degrees from the centre of gaze, as an exponential of scale 2.4°. It peaks at 0.35 — this site's median observer's value, used unchanged — and is down to 0.005 by 10 degrees. A cone at the centre of gaze and a cone 10 degrees away are looking through different filters, so they have different colour-matching functions. They are in the same eye.

Drawn at its defaults, in where on the retina the light landed. It reads 3 options and no others: show, off, scale.

Called by 2 essays

the blast radius of changing it

What the eye does

One person is two observers

The macular pigment is a yellow screen over the fovea and nowhere else, so a cone at the centre of gaze and a cone ten degrees away have different colour-matching functions in the same eye. A match made in the middle comes apart at the edge by six units — and fitting one filter to the gap between the CIE's two standard observers gives a density of 0.40 against a measured 0.35.

 What the eye does

The filters inside the eye

The macular pigment leaves 2.4 per cent of itself after adaptation — the smallest share of anything in this site's census of light changes, and less than half the next smallest. Fifty years of lens yellowing leaves 7.9 per cent, and the difference between the two says what a gain is actually good at.

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