Use of red light at night helps keep your night vision intact. Eyes have rods and cones, and their ratio varies from species to species. Rods work in low light, but cannot distinguish colour. Cones...
Type: Posts; User: stretch
Use of red light at night helps keep your night vision intact. Eyes have rods and cones, and their ratio varies from species to species. Rods work in low light, but cannot distinguish colour. Cones...