Monday; phoshene;

Phosphene

The lights you see when you close your eyes and rub them;

 Physiology .

a luminous image produced by mechanical stimulation of the retina, as by pressure applied to the eyeball by the finger when the lid is closed.

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Origin:
1870–75;  < French phosphène,  irregular < Greek phôs  light (contraction of pháos ) + phaínein  to show, shine

A phosphene is a phenomenon characterized by the experience of seeing light without light actually entering the eye. 

Phosphenes are flashes of light, often associated with optic neuritis, induced by movement or sound.

Courtesy Wikipedia