Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 20

Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 21
cExams.net
Do You Know
Questions & Answers on General Knowledge.

Question:
Does your pupil opening and closing have anything to do with it focusing on a more distant object?
Answer:
The size of your pupil does not depend on the distance to an object. It depends only on how bright the scene in front of you is. But the size of your pupil does affect your ability to focus. When it is relatively dark and your pupil is wide open, the whole lens of your eye is involved in light gathering. Focusing becomes very critical and you have very little depth of focus. Moreover, if your lens isn't perfect, you will see things as blurry. But when it is bright out and your pupil is small, you are only using the center portion of your lens and everything is in focus. That's why it is harder to focus at night than during the day. When you squint, you are artificially shrinking the effective diameter of the lens in your eye and increasing your depth of focus. Unfortunately, you are also reducing the amount of light that reaches your eye. If you look through a pinhole in a sheet of paper, you will find everything in focus, although it will appear very dim.
--- >>>
More Questions:
  • Are some frequencies of sound more directional than others and, if so, why?
  • Who invented opera?
  • Why are rain forests so important to the health of our planet?
  • What was the first animal with a spine?
  • My third grade art class was wondering what color things would be if there was no sunlight?
  • How are plants and animals related?
  • Why do you need to separate the different polarizations of light?
  • What are fossils?
  • What is the relationship between dark material and heat? Why does dark material absorb more heat than light material?
  • How do bones grow?
  • How is state government organized?
  • Why is it said that something with proven quality has passed the “acid test”?
  • Why does water stay in the straw when a finger is pressed over one end? How does sealing off the one end make the pressure less?
  • How do you know when a bear is angry?
  • How does a bee become queen of the colony?
  • What are the various functions of the roots?
  • Which are the largest and the smallest reptiles?
  • Why is an overly eager person or group said to be “gung-ho”?
  • Are asteroids planets?
  • How is it that gas moving very rapidly is unable to "communicate" with gas or surfaces in front of it?
  • Were the Native Americans religious?
  • What is the physical nature of magnetism? Is it a wave or particle phenomenon or an undefined energy like gravity?
  • Does food coloring change the color of food?
  • Could the greenhouse gas buildup ever make Earth as hot as Venus?
  • How does a fluorescent light work?
  • Stunts Mania
  • Shanghai
  • Best Photo Apps
  • Country And Capital - Quiz
  • Important Tips for Hiring the Best Employees
  • Strangest New Years Traditions

  • Wardrobe Management

    Update your wardrobe

    Donate old or ill fitted clothes, update your wardrobe and bring in freshness in style. Make a list of new style trends or missing elements and budget them down.Pre plan your shopping expenditure and things to buy, to save over boarding expense.


    Chourishi Systems