Difference between revisions of Distance vision

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Your eye can focus on one distance at a time through [[accommodation]]. Standard [[full prescriptions]] have a minimum power of 0.25D, which would compensate for an [[edge of blur]] at 4 meters.  6 meters or 20 feet is considered as far as you possibly need to measure vision.  Beyond that the number of the [[rods and cones]] in the back of your eye is a bigger limiting factor on vision than any tiny additional refraction bonus you could get.
'''Distance vision''' is, for practical purposes, anything over 6 meters or 20 feet. Because the difference in lens power from 6m to infinity is less than 0.2 [[Diopters]], the limiting factor is less about ability to focus than simply the resolution of the retina (the number of the [[rods and cones]] in the back of your eye).


As far as the [[ciliary muscle]] is concerned, your edge of blur is distance vision, no matter what the absolute distance, but you will have [[convergence]] at a near vision angle when looking at edge of blur through [[differentials]].  This is a possible mechanism of action for improvement, when the visual cortex notices the discrepancy between focus and convergence.
As far as the [[ciliary muscle]] is concerned, your [[Blur Horizon|edge of blur]] is distance vision, no matter what the absolute distance, but you will have [[convergence]] at a near vision angle when looking at edge of blur through [[differentials]].  This is a possible mechanism of action for improvement, when the [[visual cortex]] notices the discrepancy between focus and [[convergence]].


In the EndMyopia system, we use [[normalized]] glasses for outdoor work, for reading street signs, for looking out windows, and other distance vision tasks.
In the EndMyopia system, we use [[normalized]] glasses for outdoor work, for reading street signs, for looking out windows, and other distance vision tasks.


=See Also=
=See Also=
[[20-20-20 Rule]]
* [[3 hour rule]]
* [[20-20-20 Rule]]
 
* [[Close-up]]
 
[[Category:Articles]]

Latest revision as of 17:19, 1 March 2022

Distance vision is, for practical purposes, anything over 6 meters or 20 feet. Because the difference in lens power from 6m to infinity is less than 0.2 Diopters, the limiting factor is less about ability to focus than simply the resolution of the retina (the number of the rods and cones in the back of your eye).

As far as the ciliary muscle is concerned, your edge of blur is distance vision, no matter what the absolute distance, but you will have convergence at a near vision angle when looking at edge of blur through differentials. This is a possible mechanism of action for improvement, when the visual cortex notices the discrepancy between focus and convergence.

In the EndMyopia system, we use normalized glasses for outdoor work, for reading street signs, for looking out windows, and other distance vision tasks.

See Also