Can you describe such a situation? As far as my thought process goes, the horn is meant to attract attention, and lights only help that purpose.
If you are driving on a dark road with traffic coming on the opposite lane (the only situation I can conceive where high beam blinding is a problem), why would you sit on the horn for more than 1/2 a second?
If you are driving on a dark road with traffic coming on the opposite lane (the only situation I can conceive where high beam blinding is a problem), why would you sit on the horn for more than 1/2 a second?