[svandamme]

one lumens is the light equivalence of 1 candle
10 000 lumens is a lotta candles
although it's not that much standard 100 wat regular lightbulbs (around 6 in 110v North america, around 7.5 in 220v row)
not sure if lumens is the right thing to watch for in terms of light , anti winter blues , therapy
as lumens is simply a brightness measurement

it does not specify what part of the spectrum it produces, and in terms of anti winter blues, i think one needs to look for a specific part of the spectrum , to replace certain things that are normally delivered by the sun ( other then just the light part)