Here are five small sketches, based on some of my phosphenes. To make a picture, I sit with my eyes firmly closed and with a pencil or a pen draw lines and shapes on paper that correspond as nearly as I can make them to the floating images I see with my eyes shut. I use my fingers on the page to roughly keep the image in bounds. The square ones here are 11 x 11 cm, the other is A4 size.
A drawing takes perhaps only 10 to 15 minutes, and although a short time, I find it surprisingly energy-consuming in its heavy concentration. Afterwards, I use the line drawing as a basis for what you see here. Not much more is to be done, but I fill in some spaces with dark pencil, sometimes a bit of shading. Or I add a wash of watercolour.

Pencil
11 x 11 cm

Pencil.
11 x 11 cm

Ink + watercolour
A4

Pencil
11 x 11 cm

Pencil
11 x 11cm
You might say these are nothing but scribbles and squiggles, even the type of doodles you might make during an enforced session in a conference chamber. Having had my share of experience of the latter, I can tell you these, at least for me, are very different.
Why not try it yourself?