What will happen when you enter a dark room after you've been in a bright room and what causes this?

Answer 1

Going from a bright area to a darker one means that not as much light is available for your eyes. The pupils will dilate (widen) to let in more of the available light, but even then your eyes may take a minute to adjust.

In very dim light, the cells in the retina that detect color (cones) will not function and other cells (rods) will begin to work, but these can only detect all frequencies at one time, and provide only black-and-white vision. Since the rods are normally deactivated in bright light, it can take awhile to achieve your best "night vision."

Answer 2

When you enter a dark room after being in a bright room, your eyes will take some time to adjust to the lower light levels. This is due to the pupil size adjusting to let in more light in the dark room, and the photoreceptor cells in the retina needing time to become more sensitive to low light conditions.

Answer 3

the pupils are contracted and when you go into the dark room your pupils take time to dilate or open, not enough light gets in your eyes to see and you are momentarily blind