You can wear Twilights during the daytime if you particularly want to, but we do not recommend it. They are very powerful and are liable to make you drowsy during the day if worn for prolonged periods! In addition, you should NEVER wear them when driving, as the light-filtering properties will make it difficult if not impossible to see certain traffic signs and lights, such as green lights on stop signals. You should never wear these glasses when you need to be alert for safety reasons, or where you need to see certain lights or signals for safety. They are primarily designed to be worn indoors, at home, in the evening to help prep your brain for sleep.