Fun fact: Strong infrared light still damages the eye even if you don't see it. As a bonus, the pupils may be fully dilated due to darkness and let even more IR light hit the innards.
To add to this, you get more out of your horn mileage if you get in intervals, especially to your favorite rhythm. It's simply not a Saturday night without me driving blind on a winding road in the dark honking to Staying Alive.