Dazzle is part of the Light Adaptation rules for Shooting in Darkness.
It involves a HT roll where explosions, (bright) lights and (intense/muzzle) flashes occur. Penalties depend on TL of the flash.
Big successes involve no change in dark adaptation.
Small successes ruin it.
Failure gives an extra -4 to Vision (can't exceed the -10 for blind) for MoF minutes.
- Crit fails blind you for MoF seconds first, then apply the minutes
- in cases where there is no MoF at all (for example you have HT 20 and roll an 18) due to no "minimum 1" for the seconds/minutes there is presumably no effect aside from losing the dark adaptation as per a small success.