Pupils dilation

Eye has an amazing character in responding to light. When we are out in hot sunny day we open our eye very little. The eye sensor creates a reflex action to not to destroy the retina due to exposure to more light. And during dark nights, our pupil area of the eye through which light reaches retina becomes larger so as to send more light and makes capable to see. When there is a power cut and it is dark... your pupil is wide open to allow more light and when the power comes back, we don't feel comfortable as our eye is in a state to allow more light. It takes a little time to our eye later which it adjusts the pupil area to allow sufficient amount of light to make us see things good. People having eye sight is due to insufficient amount of light falling on the retina... they use spectacles to adjust the light to get concentrated on the retina thus capable of looking things clearly..


courtesy - http://www.medterms.com/script/main/art.asp?articlekey=5135