A variation in colour contrast is introduced under varying lighting conditions by this effect. When viewed at dusk, the contrast is reversed, with the red petals appearing a dark red or black and the leaves and blue petals appearing relatively bright. For example, in bright sunlight, geranium flowers appear bright red against the dull green of their leaves, or adjacent blue flowers.
https://upload.wikimedia.org/wikipedia/commons/2/2e/Purkinje_effect.gif
Our perception of colour varies with lighting intensity. The Purkinje effect describes how the wavelengths of light that the human eye is sensitive to change with light intensity. Peripheral rod cells are stimulated by lower light levels, and this results in a shift in the eye's peak sensitivity to green from yellow for daytime vision. For instance, an object in moonlight may appear greyish-green, and a red flower may appear black during twilight.
The Purkinje images—a sequence of reflections from the eye's structures—are a different phenomenon. The first Purkinje image is caused by reflection from the cornea's anterior surface; the second, third, and fourth Purkinje images are caused by reflection from the cornea's posterior surface, anterior surface of the lens, and inverted lens, respectively. Eye tracking technology can read the reflections to see how the eye moves.
Purkyně's research brought him great fame. It is stated that all that is required for a letter to reach Purkyně, Europe, is for the sender to address it to him.
Purkyně's research brought him great fame. It is stated that all that is required for a letter to reach Purkyně, Europe, is for the sender to address it to him.
