It normally takes 20 – 30 minutes for the eyes to dilate. It then just takes 5 - 10 minutes for the doctors to examine them. The pupils will remain larger than normal for 4 – 6 hours causing increased light sensitivity but vision is back to normal usually within the hour.oering or Hageman to have a better view inside your eye to make sure your eyes are healthy. It is much like opening a door to see inside a room instead of looking in through a small window. With dilation, one can see the optic nerve head, blood vessels, the macula and out to the periphery of the retina.