Why did people put black strip on their headlights in the 90s

The practice of applying a black tape on the headlamp slowly died down.

Sanidhya mukund recently shared this with other BHPians.

This is about something that I have been trying to find an answer to for quite some time now.

My garage consists of two cars that were bought in the 1990s. One is a 1995 Esteem and the other is a 1993 Tata Estate. Both of them are non-starters now and have been sitting abandoned for the past decade or so, but whenever I see them, I notice this strip of black paint or tape at the top of their headlights. I have also noticed this in quite a few cars from the 1990s.

My question is, what purpose do they serve? Why did people put these strips on their headlights?

And if it did indeed serve a purpose, why didn’t people continue it even beyond the 90s?

Thanks to Sanidhya mukund once again! Check out BHPian comments for more insights & information.