Hmm... I don't know if this is what you're talking about, but I may have had a similar experience. Sometimes when I'm idily looking at something, I can see auras around things. Well, they aren't auras exactly, but I can see... light bending around the object. It's like I can see a current of light bending to the contours of an object. It is very very faint, but this "aura" looks different from all of the other light in the room in the way that it appears distorted and adjusts to the contours of the object perfectly. This most often happens with trees and sometimes people. I don't know if this is an optical illusion based on how light is percieved and how light rays actually bend, and how the retina processes all of this, but I've been able to see this since I can remember. I can't recall seeing this with non-living objects though, so it doesn't agree with your towel story. Also, sometimes I see these "auras" and sometimes I don't. I can't really control when it happens, it just does.
I can corroborate this. The color on the cars' edges gets projected outward elongated, streaked, in transparent radiance, like a laser-projection show. It looks as if you could suddenly freeze the image of the street, get Photoshop and copy the white edges of the car and smear it outward with a blur/smudge brush to make it a shiny transparent "car aura" or "edge radiance shine" that goes up in an angle from objects that are hit by sunlight.
Possibly damage to my cornea, progressing with age, I think. People who had corrective laser surgeries to their eyes ["Now You Can Throw Away Your Glasses!"] - report that in the dark they either don't see nothing or see distorted and misaligned, displaced, blurry contours. During the day in sunlight, when I look down, but hold my head straight -, the outline of my hands start to glow [blur] a little, objects too. It feels very much like one of those eye diseases slowly manifesting with age.
What I wanted to corroborate here that during meditation
too much of the totally darkened room lights up with eyes shut. Sometimes as if a "blue spiritual sun" would go up, it fills my room with background light. Then big animated islands of ALIVE white-silver light mist flow and fade in - then out of reality [in a perpetual cycle, like a sloow heart throbbing] with the dynamics and speed like on this YT video, but with real smooth motion. Everything is grey-white or slightly blue, so imagine this mist I made
like these lights in this YT video below: (replace orange with the "faint grey-blue white" of above pic in your mind)
When startled from sleep,
- or in half sleep I suddenly remember I forgot to set the alarm clock - and get up in the total darkness
and I see a disturbing white-electric light arc creature-show of floating eels (also fighting),
like the more intense ALIVE lightning arcs in on this image:
point lights, large shapes,
blinding blue-white alive and frighteningly intelligent looking
electric arcs animated everywhere, moving, hopping, striking, contacting, bridging and disappearing into nothing and coming back in the rhythm of a slowly blinking car-light [traffic-indicator]. In a totally darkened room.
Just like the blue mist in this image without the yellow scenery:
Last time, this weekend, the electric blue-white arc-light show appeared to show auras of two thin beings, when every described light-creature was writhing around me
During these times, when I look at my body I see these blue-light "arteries": I exaggerated the brightness a little for clarity. These are always stable, like arteries on a live x-ray, when I move my limbs or body, these "arteries" move with the body mass, but are otherwise fixed.
Concentrating on them slowly reveals the smaller webbing of "arteries", like on this image, just in my limbs, stomach or chest that I can look at while sitting in darkness.
However sometimes the above chaos around me quickly gets so unnerving that I always switch on the little lamp on my table so I can calm down.