Lights when meditating?

Okay so I’ve always been curious, but when meditating (with eyes closed) – what are those wavy/light patterns that happen in your vision? It’s like wavy white light (not that bright) that seems to happen when I meditate. With my eyes closed.

When I focus on them, then the light increases/becomes more vivid ? – also seemed like I saw light purple light to (when I was focusing on my third eye) – and felt pressure/tingling on my third eye area.

It’s basically like light like patterns that happen while meditating mostly. It’s not the same as the orb like light I see when a spirit/energy manifests but IS similar – although this seems to happen more with meditation.