There is an amusing activity that I liked to involve myself in from time to time in which I play with light. Or rather the reflection of light. I have done certain meditive practices looking directly in the heart of a flame, but that rather messes with my head and usually ends up with some partial vision loss while my eyes adjust to looking at a normally lit space. So as fun as it is stare into a flame as a focus, I have decided many years ago what my preferred practice was. I took an abalone shell (and being from where I am from that was never a problem finding one of them) though I am certain a dark ceramic bowl would work just as well but I prefer my abalone. I took special care to plug all holes in the shell by coating the entire bottom of the shell with a thick layer of wax. I then filled it with water and set it on a table.
Next to the shell I set a candle. Just one candle will do. Position the candle so that the flame can be easily seen reflected on the water. Now the reason I love abalones so much is that they are endowed with a natural coloring in the inside of their shells that is multi-hued. Therefore the light is playing against these hues contorting them through the water. I just relax my mind and watch it and see where my imagination leads.
This is not all that different from the way I used to watch leaves as a child moving in the wind from the treebranch with a restful mind to catch images formed within the movements of the leaves. The game with light is just more convenient. I often do it as a before bed activity.