I'm coming to you with a strange physical/optical phenomenon I noticed today for which I'm looking for an explanation. I can't seem to find references to this, and it was pretty surprising to see for the first time.
Background: I'm a photographer, and I am trying to experiment more with monochromatic light sources. I hacked together a fixture for a relatively bright low pressure sodium (SOX 90 Watt) lamp, and it worked beautifully, producing a bright near-monochromatic yellow-orange light. The first thing I did once I had it working was to take it into the bathroom. There, I experienced the phenomenon: when I looked in the mirror, there was an interference pattern around my eyes in the reflection. It looked a lot like Newton's Rings. When I opened only my left eye, only my left eye's reflection had the rings around it. When I tried to replicate this with a camera, I did not get the same effect, which leads me to believe it's something specific to the optics of the eye.
What's more, I have a pretty monochromatically red CFL in my bathroom, which I use successfully as a safe light. I do not see this effect with the red light source.
Is this a well-known phenomenon that I just don't know the right words to search for? Is this a function of wavelength? I have also read that technically, low pressure sodium bulbs have two emission peaks, at 589.0nm and 589.6nm. Does the gap between these cause some sort of constructive/destructive interference?
Thank you for your time. As spooky as this was to discover, I am genuinely interested in how and why this was happening.
UPDATE: I got my housemate to come in the bathroom with me, and he confirmed my observation. What's more, we could see the rings in our own eyes, but not each other's eyes.