Go Back   Physics Help Forum > College/University Physics Help > Advanced Optics

Advanced Optics Advanced Light and Optics Physics Help Forum

Like Tree1Likes
  • 1 Post By Woody
Reply
 
LinkBack Thread Tools Display Modes
Old Aug 25th 2016, 08:33 PM   #1
Junior Member
 
Join Date: Aug 2015
Posts: 8
Smile far point of hypermetropes

why in hypermetropes the far point is behind the eye in virtual space, rather than in front of the eye.?
Harivarshand is offline   Reply With Quote
Old Aug 26th 2016, 09:07 AM   #2
Senior Member
 
Join Date: Aug 2010
Posts: 264
You might want to start with definitions: what is a "hypermetrope"? What is a "far point"?
HallsofIvy is offline   Reply With Quote
Old Aug 26th 2016, 10:50 AM   #3
Junior Member
 
Join Date: Aug 2015
Posts: 8
hypermetropia is a condition where in parallel rays of light comming from infinity are focused on retina where as rays comming from near are focused behind the retina
Harivarshand is offline   Reply With Quote
Old Aug 26th 2016, 01:09 PM   #4
Senior Member
 
Join Date: Aug 2010
Posts: 264
So your question is actually a medical one, not physics.
HallsofIvy is offline   Reply With Quote
Old Aug 27th 2016, 02:38 AM   #5
Junior Member
 
Join Date: Aug 2015
Posts: 8
yes medical,can u explain
Harivarshand is offline   Reply With Quote
Old Aug 28th 2016, 03:40 PM   #6
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 366
It is all a question of the shape of the eye and the lens.
There are muscles around the edge of the lens that can pull upon it to change its shape and thereby change the distance at which the eye focuses.
wikipedia Lens anatomy
For a perfect eye, when the muscles around the lens are completely relaxed the eye is focused on "infinity" (parallel rays).
The arrangement of the muscles and the structure of the lens mean that increasing tension in the muscles squashes and thickens the lens causing closer objects to be focused on the retina.
If the shape of the eye or the lens is not correct, then the focus will not be correct and you may require spectacles.
Spectacles tend to be required more in old age, as the lens gets stiffer and so will not change shape sufficiently to account for any deficiency in the shape of the eye.
wikipedia Far-sightedness
topsquark likes this.
Woody is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > Advanced Optics

Tags
hypermetropes, point



Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
How many Planck's in a point? Instantonly Quantum Physics 17 Sep 8th 2016 02:20 PM
moment about a point = 0 ling233 Kinematics and Dynamics 1 Oct 7th 2015 07:21 AM
Moments about a Point febbie22 Kinematics and Dynamics 3 Aug 4th 2010 12:29 PM
Material point Apprentice123 Advanced Mechanics 0 Jun 12th 2009 11:52 AM
Help with point charges colstu0510 Advanced Electricity and Magnetism 1 May 7th 2009 01:03 AM


Facebook Twitter Google+ RSS Feed