Remember its the pituitary and several other centers in the brain that need to be "tricked" into a new season.

Like forcing flowering you need to pay attention to the timing of the lights and not just the lights themselves.
Early morning lights around the time mid Spring sunrise would be highly advised.

The optic nerve is what triggers the other centers and not merely the skin so don't wear goggles - on the other hand - (if the ultraviolet is strong you never want to just stare at the lights).

The wavelenghths that help reset the bio clock are toward the ultra violet but the warm infra reds sure feel nice.

I use a little floor model verilux with a flexible arm very close to the face. Its not powerful but its true color sunshine right out of the box for about $60 to $90.