I have found that adding white, sun-like light, using LED bars for example can help. One can't easily simulate sun light but I found adding several light source

I have found that adding white, sun-like light, using LED bars for example can help. One can't easily simulate sun light but I found adding several light sources, at least 4 can make a difference. In my experience, working in bursts with "strong" breaks help, for example grabbing a cup of coffee and spending 10min outside every 1.5h.