Light, especially bright sources of glare, in the short-wavelength part of the spectrum saturates the “rod” light detectors in the eye, causes vision to become bright-adapted. To adapt back to fully capable night vision takes something like 20–30 minutes.
Additionally, beyond rods and cones, there are a 3rd set of light detectors in the eye, the “photosensitive retinal ganglion cells”, which regulate melatonin and sleep cycles. These are particularly sensitive to light in the 400–500 nm range. Looking at such a light source at nighttime can suppress melatonin production until about an hour after you stop the light. This is the reason that smartphone, television, and computer displays are all so disruptive to sleep when used before bed.
Additionally, beyond rods and cones, there are a 3rd set of light detectors in the eye, the “photosensitive retinal ganglion cells”, which regulate melatonin and sleep cycles. These are particularly sensitive to light in the 400–500 nm range. Looking at such a light source at nighttime can suppress melatonin production until about an hour after you stop the light. This is the reason that smartphone, television, and computer displays are all so disruptive to sleep when used before bed.