When you enter a darkened room (e.g. a movie theater) you will find it hard to see at first but shortly afterward you will be able to see much better. This phenomenon is referred to as?

This phenomenon is referred to as "dark adaptation." When you enter a darkened room, your eyes initially struggle to adjust due to the bright conditions you were previously in. Over time, the photoreceptors in your retina, particularly the rods, become more sensitive to low light levels, allowing you to see better in the dark. This process can take several minutes to fully occur.