I realised that if I fix my gaze on a random spot in the night sky, I start to see more stars (those presumably dimmer ones) appearing, if I look long enough. (Note: there is in the presence of dim external city lights.)
Is this due to our eyes adjusting to the dimness of the night sky (can be explained with biology) (first case) or could it be due to a slower registering of the light from dimmer stars, which were of lower intensity and hence at first glance was not detected and recognised as distinct light sources/stars (second case)?
I do not think that it is the first case - which can be explained (I suppose?) with the same reasons to why we get momentarily "blinded" when walking into a dark room from a brighter surrounding (reason: not enough rhodopsin, the chemical that helps us perceive light in the dark). I disagree because I was already out in the dark in most occasions and my eyes would have already adjusted to the surrounding brightness(dimness). Hence in that case, wouldn't my eyes be sensitive enough that I will be able to see the dimmer stars immediately upon looking into the night sky/at first glance which I don't?
But since that is not the case according to my experience, I am thinking if it could be the second case? An analogy I thought of (more to help express myself) for this case is by likening our eyes to a blank canvas and the light from the stars are - instead of light waves - single straight streams of (separate) ink droplets, with greater distance between droplets from dimmer stars (lower intensity light) and shorter distance between droplets from brighter stars (higher intensity light). So the longer I look at the sky, the more droplets collect on my canvas, and the lower intensity light would take longer to reach the same intensity as higher intensity light (e.g. in 1s, 5 drops collect on the point corresponding to high intensity lightand only 1 drop on the spot of lower intensity light). Assuming the droplets get absorbed the moment it touches my canvas and only at that spot of contact, it will take longer for our eyes to register that there is indeed a (dimmer) star at x location. In that case, it is not really of our eyes adjusting to the surrounding brightness, but instead of this sudden awareness when we realise over time the difference in light intensity from certain dimmer star spots - aka the moment I realise there are actually more stars than the one I saw at first glance.
I would like to know the correct scientific explanation (first/second case or none) behind this phenomena of seeing more stars after longer exposure to the night sky, and whether my analogy is flawed?