why do people lose precise vision sometimes?
551139
hey you mean you had good vision couple of hours ago and now its blurry... go to a doctor right now...
582826
Some forget and some have bad night vision. Don't be annoyed,be in action. Flash your lights to remind them. Peace.
379741
It happens very fast.  Most people see at20/20 almost immediately but some it takes longer.  It can take up to a year for your eyes to adjust and most people have at least some fluctuations in that year.  But most people have nearly perfect vision right away.
286285
i don't think its that complicated we can only see a fraction of what is around us because of our very poor eye sight and other senses such as smell and touch. i agree with you that there are many other level that we cannot see or feel, but that is our loss. try not to concern yourself with things you have no way of being part of, as there are more things in heaven and earth than you could possibly ever imagine if we could see all levels it would blow our minds.
511294
It indicates the person is near sighted.
858202
You know you need glasses when you start seeing things in a blur. Or you start getting heachaches if you read to much.\n\nOnly the optican can give you a diffinite answer though
497571
I think you're asking why after age 35 people need glasses.  Around the age of 40 (a little earlier for some people and later for others), the lens of the eye basically loses its elasticity.  In younger people, the lens changes shape to help you focus at different distances.  When the lens gets stiffer, it can't focus at closer distances so people need reading glasses to help them see up close.
316328
this is not a stupid question.  afrend has the right answer. i figured it had something to do with focus
8548
Close.  I would say it's because the photons from the object hit a smaller area of the cornea.  If you think of the surface of the cornea as a screen onto which the world in front of the viewer is projected through a lens, as an object is moved away the angle between its top and bottom gets smaller and so the relative size of the object in that projection gets smaller.
894401
there's an obstruction on the nerves that causes your eyes to function abnormally
264522
The healthy human eye is only restricted by external factors (ie.: poor visibility due to haze, dust or fog), just think how far the stars are!
504075
My guess it's a response to stress.  Sight is the main sense in people lucky enough to have it and we rely too much on it.  If shocked, it might be good to have a clear sight in case something comes your way (imagine you're a caveman and big sabertooth cat is cominagetcha)
199261
Adaptations are hard-wired into our brains, and thus under some artificial manipulations can cause inappropriate interpretations of the visual scene. Or, as Purkinje put it: "Illusions of the senses tell us the truth about perception" (cited by Teuber, 1960).
399440
Im not sure if head trauma can cause this later on in life , but I do know that one is usually born with this condition. I have two family members which have suffered from this and I myself have what is known as a "lazy-eye" and all of us have been born with this eye condition. However, there are corrective measures as well as surgeries and it's too bad this little darling wasnt given the chance at having one.
808919
johnpaul_ is revealing his own lack of education in his answer.\n\nYes, it is possible for glasses to give you better than 20/20 vision. The 20/20 number is a comparison between two people... the first number represents you, and how close you have to be to see a given object clearly. The second number represents a person with "normal" sight and how far away they have to be to see that object clearly. For example, if person who has 20/200 vision (legal blindness) has to stand 20 feet away from an object in order to see it clearly, a person with normal vision can stand 200 feet away and see the image as clearly.\n\nSo there is nothing special about 20/20 vision. It is just an aribitrary standard based on the average range of vision (which was established many years ago, an may not be reflective of the current US population). So, good glasses will not necessarily "correct" you to 20/20 vision. They may be "over prescribed" and land you at 25/20, or under-prescribed and land you at 20/25. There is nothing wrong with the eye chart. If you are too over- or under-prescribed, you may experience a lot of eye strain. If that happens you need to get a new pair or you may get a lot of headaches.
82009
It could be "Floaters" small pieces of dead skin that have worked their way into your field of vision, the eye sloughs off dead tissue like the rest of your body and sometimes it floats around in your vision, my mum has them and she just has to learn to live with them, best just to go to an optition for confirmation.
1167481
I can't explain it, but with more info, you can create your own dillusions of what you don't and don't have to worry about. Check out\n\nhttp://www.webmd.com/hw/vision/hw91926.asp?navbar=hw91869