If you're growing plants under lights, surely there will be a significant amount of light in the area?
Our tomato greenhouse is lit during the winter months. This increases the productivity of our plants, allowing us to grow tomatoes all year round. To recreate the light conditions of a spring day, the lights are used from around midnight until around 3pm each day (or earlier if it's a particularly sunny day). Then the plants go to sleep with the natural setting of the sun.
To minimise wasted light, the tomato greenhouse is fitted with a system of blinds which exist to trap the light and warmth inside. We don't want to waste the light we produce so the blinds are designed to retain around 95% of our artificial light within the greenhouse. Peppers and cucumbers are not grown under lights.