Any form of tint will reduce the amount of light passing through. There are very strict rules regarding how much tint a car windscreen can have.
If you take a look at your cars screen the odds are it will have a tint to it. That amount of tint doesn't seem very much at all, but is only just legal.
I have tested many with the "Tintman" calibrated gauge and every (standard) car windscreen I tested showed a tint level just within the permitted range.
If you compare those "night driving" glasses with your windscreen you will see they have a much greater level of tint.
I wouldn't consider using them for the above reason, but that's me, others may well feel differently