Can a Variac switch be used in place of a dimmer?

I have a Variac that I use as a fan speed controller....but I was wondering if it could also be utilized as a dimmer for a light fixture that doesn't have a dimmer....by just plugging the light into the Variac and then plugging that into the outlet.

For example: would it work on my old Area 51 SGS 160?

thanks

short answer: no,

led driver output is independent of AC input. you could look at the drivers in the A51 and determine if they are dimming capable, and if not, replace the drivers with dimmable ones