Which of the following is true about your night vision after being dazzled by the full beams of another vehicle?
Everyone’s vision deteriorates in the dark. First of all, you do not see as well and, secondly, it takes much longer to adapt from light to dark than it takes to adapt from dark to light.
“After being dazzled, it takes a minute or two to adapt before your night vision works fairly well again.” (Driving Licence Book, page 151)
More examples of explanations: