Presbyopia - Revision history

User: Reverted edits by Ninebalasan (talk) to last revision by User

2022-03-28T16:20:14Z

Reverted edits by Ninebalasan (talk) to last revision by User

← Older revision		Revision as of 16:20, 28 March 2022
Line 1:		Line 1:
	~~{{resize\|160%\|~~Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] (reduced minus for myopes), progressive lenses, or [[bifocals]].}}		Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] (reduced minus for myopes), progressive lenses, or [[bifocals]].

	==~~{{resize\|200%\|~~Correction}}==		==Correction==
	~~{{resize\|160%\|~~As you age, the lens in your eye becomes less flexible. This makes [[accommodation]] more difficult and brings on "arms are not long enough to read" symptoms. Someone may be both [[myopic]] and presbyopic, and have deficits in both near and far vision. Your [[Prescription]] will have an "Add" section specifying bifocals or multifocals if you have diagnosed presbyopia, or if your doctor thinks it best to reduce eye strain.}}		As you age, the lens in your eye becomes less flexible. This makes [[accommodation]] more difficult and brings on "arms are not long enough to read" symptoms. Someone may be both [[myopic]] and presbyopic, and have deficits in both near and far vision. Your [[Prescription]] will have an "Add" section specifying bifocals or multifocals if you have diagnosed presbyopia, or if your doctor thinks it best to reduce eye strain.

	===Two glasses===		===Two glasses===
	~~{{resize\|160%\|~~It is an option to have two pairs of glasses, one for close-up, and one for distance, instead of trying to combine both near and far corrections in one pair of glasses.}}		It is an option to have two pairs of glasses, one for close-up, and one for distance, instead of trying to combine both near and far corrections in one pair of glasses.

	===Bifocals===		===Bifocals===
	~~{{resize\|160%\|~~Glasses with a lower section that is specifically for close work.}}		Glasses with a lower section that is specifically for close work.

	===Progressive lenses===		===Progressive lenses===
	~~{{resize\|160%\|~~Glasses with a gradient from zero to near plus addition spherical power from top to bottom.}}		Glasses with a gradient from zero to near plus addition spherical power from top to bottom.

	===Multifocals===		===Multifocals===
	~~{{resize\|160%\|~~Contacts that have sections for near and far work, which the [[visual cortex]] will selectively use when looking at different distances.}}		Contacts that have sections for near and far work, which the [[visual cortex]] will selectively use when looking at different distances.

	== Measuring ==		== Measuring ==
	~~{{resize\|160%\|~~To determine '''power of accommodation''', also sometimes called '''amplitude of accommodation''', measure '''far power''' and '''near power'''.}}		To determine '''power of accommodation''', also sometimes called '''amplitude of accommodation''', measure '''far power''' and '''near power'''.

	~~{{resize\|160%\|~~'''Far power''' is straightforward, and it’s the typical [[cm measurement]]: just measure the furthest distance you can see clearly without blur, with a lens to adjust as needed. The far power is ''1/(distance to blur) - (lens power)''.}}		'''Far power''' is straightforward, and it’s the typical [[cm measurement]]: just measure the furthest distance you can see clearly without blur, with a lens to adjust as needed. The far power is ''1/(distance to blur) - (lens power)''.

			* For example, 80 cm with a -0.25 lens is calculated as 1/(80 cm) - (-0.25 D) = 1.25 D + 0.25 D = 1.5 D.
			* It might be useful to use a plus lens to measure low myopia. For example, 80 cm with a +0.75 lens is calculated as 1/(80 cm) - (+0.75 D) = 0.5 D.

	* For example, 80 cm with a -0.25 lens is calculated as 1/(80 cm) - (-0.25 D) = 1.25 D + 0.25 D = 1.5 D.}}		'''Near power''' is the same, but measure the '''closest''' distance you can see clearly without blur.
	* It might be useful to use a plus lens to measure low myopia. For example, 80 cm with a +0.75 lens is calculated as 1/(80 cm) - (+0.75 D) = 0.5 D.}}

	'''~~{{resize\|160%\|~~Near power}}''' ~~{{resize\|160%\|~~is the same, but measure the '''closest''' distance you can see clearly without blur.}}

	* For example, if the closest you can see is 10 cm without lenses, it’s calculated as 1/(10 cm) - 0 = 10 D.		* For example, if the closest you can see is 10 cm without lenses, it’s calculated as 1/(10 cm) - 0 = 10 D.
	* It might be useful to use a big minus lens to measure young people (don’t look through it for too long!). In the example above, you expect to see as close as 50 cm with a -8 lens, which is 1/(50 cm) - (-8 D) = 2 D + 8 D = 10 D.		* It might be useful to use a big minus lens to measure young people (don’t look through it for too long!). In the example above, you expect to see as close as 50 cm with a -8 lens, which is 1/(50 cm) - (-8 D) = 2 D + 8 D = 10 D.

			The '''power of accommodation''' is (near power) - (far power). With the first example in each of the above, it would be 10 D - 1.5 D = 8.5 D.

	~~The '''power of accommodation''' is (near power) - (far power). With the first example in each of the above, it would be 10 D - 1.5 D = 8.5 D.}}~~		A person is generally considered to have presbyopia [[wikipedia:if and only if \| iff]] his power of accommodation is less than 2.5 D.

	~~{{resize\|160%\|~~A person is generally considered to have presbyopia [[wikipedia:if and only if \| if]] his power of accommodation is less than 2.5 D.}}

	===Caveats===		===Caveats===

	~~{{resize\|160%\|~~This technique might need to be refined for cylinder, if spherical equivalent is not used.}}		This technique might need to be refined for cylinder, if spherical equivalent is not used.

	~~{{resize\|160%\|~~The cornea and lens actually have more power because the total power has to focus the image on your retina, but they cancel out in the subtraction step, so it’s easier to ignore them.}}		The cornea and lens actually have more power because the total power has to focus the image on your retina, but they cancel out in the subtraction step, so it’s easier to ignore them.

	== Videos ==		== Videos ==

Ninebalasan at 20:53, 26 March 2022

2022-03-26T20:53:52Z

← Older revision		Revision as of 20:53, 26 March 2022
Line 1:		Line 1:
	Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] (reduced minus for myopes), progressive lenses, or [[bifocals]].		{{resize\|160%\|Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] (reduced minus for myopes), progressive lenses, or [[bifocals]].}}

	==Correction==		=={{resize\|200%\|Correction}}==
	As you age, the lens in your eye becomes less flexible. This makes [[accommodation]] more difficult and brings on "arms are not long enough to read" symptoms. Someone may be both [[myopic]] and presbyopic, and have deficits in both near and far vision. Your [[Prescription]] will have an "Add" section specifying bifocals or multifocals if you have diagnosed presbyopia, or if your doctor thinks it best to reduce eye strain.		{{resize\|160%\|As you age, the lens in your eye becomes less flexible. This makes [[accommodation]] more difficult and brings on "arms are not long enough to read" symptoms. Someone may be both [[myopic]] and presbyopic, and have deficits in both near and far vision. Your [[Prescription]] will have an "Add" section specifying bifocals or multifocals if you have diagnosed presbyopia, or if your doctor thinks it best to reduce eye strain.}}

	===Two glasses===		===Two glasses===
	It is an option to have two pairs of glasses, one for close-up, and one for distance, instead of trying to combine both near and far corrections in one pair of glasses.		{{resize\|160%\|It is an option to have two pairs of glasses, one for close-up, and one for distance, instead of trying to combine both near and far corrections in one pair of glasses.}}

	===Bifocals===		===Bifocals===
	Glasses with a lower section that is specifically for close work.		{{resize\|160%\|Glasses with a lower section that is specifically for close work.}}

	===Progressive lenses===		===Progressive lenses===
	Glasses with a gradient from zero to near plus addition spherical power from top to bottom.		{{resize\|160%\|Glasses with a gradient from zero to near plus addition spherical power from top to bottom.}}

	===Multifocals===		===Multifocals===
	Contacts that have sections for near and far work, which the [[visual cortex]] will selectively use when looking at different distances.		{{resize\|160%\|Contacts that have sections for near and far work, which the [[visual cortex]] will selectively use when looking at different distances.}}

	== Measuring ==		== Measuring ==
	To determine '''power of accommodation''', also sometimes called '''amplitude of accommodation''', measure '''far power''' and '''near power'''.		{{resize\|160%\|To determine '''power of accommodation''', also sometimes called '''amplitude of accommodation''', measure '''far power''' and '''near power'''.}}

	'''Far power''' is straightforward, and it’s the typical [[cm measurement]]: just measure the furthest distance you can see clearly without blur, with a lens to adjust as needed. The far power is ''1/(distance to blur) - (lens power)''.		{{resize\|160%\|'''Far power''' is straightforward, and it’s the typical [[cm measurement]]: just measure the furthest distance you can see clearly without blur, with a lens to adjust as needed. The far power is ''1/(distance to blur) - (lens power)''.}}

	* For example, 80 cm with a -0.25 lens is calculated as 1/(80 cm) - (-0.25 D) = 1.25 D + 0.25 D = 1.5 D.
	* It might be useful to use a plus lens to measure low myopia. For example, 80 cm with a +0.75 lens is calculated as 1/(80 cm) - (+0.75 D) = 0.5 D.

	'''Near power''' is the same, but measure the '''closest''' distance you can see clearly without blur.		* For example, 80 cm with a -0.25 lens is calculated as 1/(80 cm) - (-0.25 D) = 1.25 D + 0.25 D = 1.5 D.}}
			* It might be useful to use a plus lens to measure low myopia. For example, 80 cm with a +0.75 lens is calculated as 1/(80 cm) - (+0.75 D) = 0.5 D.}}

			'''{{resize\|160%\|Near power}}''' {{resize\|160%\|is the same, but measure the '''closest''' distance you can see clearly without blur.}}

	* For example, if the closest you can see is 10 cm without lenses, it’s calculated as 1/(10 cm) - 0 = 10 D.		* For example, if the closest you can see is 10 cm without lenses, it’s calculated as 1/(10 cm) - 0 = 10 D.
	* It might be useful to use a big minus lens to measure young people (don’t look through it for too long!). In the example above, you expect to see as close as 50 cm with a -8 lens, which is 1/(50 cm) - (-8 D) = 2 D + 8 D = 10 D.		* It might be useful to use a big minus lens to measure young people (don’t look through it for too long!). In the example above, you expect to see as close as 50 cm with a -8 lens, which is 1/(50 cm) - (-8 D) = 2 D + 8 D = 10 D.

	~~The '''power of accommodation''' is (near power) - (far power). With the first example in each of the above, it would be 10 D - 1.5 D = 8.5 D.~~

	A person is generally considered to have presbyopia [[wikipedia:if and only if \| ~~iff~~]] his power of accommodation is less than 2.5 D.		The '''power of accommodation''' is (near power) - (far power). With the first example in each of the above, it would be 10 D - 1.5 D = 8.5 D.}}

			{{resize\|160%\|A person is generally considered to have presbyopia [[wikipedia:if and only if \| if]] his power of accommodation is less than 2.5 D.}}

	===Caveats===		===Caveats===

	This technique might need to be refined for cylinder, if spherical equivalent is not used.		{{resize\|160%\|This technique might need to be refined for cylinder, if spherical equivalent is not used.}}

	The cornea and lens actually have more power because the total power has to focus the image on your retina, but they cancel out in the subtraction step, so it’s easier to ignore them.		{{resize\|160%\|The cornea and lens actually have more power because the total power has to focus the image on your retina, but they cancel out in the subtraction step, so it’s easier to ignore them.}}

	== Videos ==		== Videos ==

User: /* Correction */

2022-03-20T22:11:40Z

Correction

← Older revision		Revision as of 22:11, 20 March 2022
Line 5:		Line 5:

	===Two glasses===		===Two glasses===
	~~Having~~ two pairs of glasses, one for close-up, and one for distance, instead of trying to combine both near and far corrections in one pair of glasses~~, is an option~~.		It is an option to have two pairs of glasses, one for close-up, and one for distance, instead of trying to combine both near and far corrections in one pair of glasses.

	===Bifocals===		===Bifocals===
	Glasses with a lower section that is specifically for close work.		Glasses with a lower section that is specifically for close work.

			===Progressive lenses===
			Glasses with a gradient from zero to near plus addition spherical power from top to bottom.

	===Multifocals===		===Multifocals===

User at 18:00, 9 March 2022

2022-03-09T18:00:32Z

← Older revision		Revision as of 18:00, 9 March 2022
Line 1:		Line 1:
	Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] (reduced minus for myopes), progressive lenses, or [[bifocals]].		Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] (reduced minus for myopes), progressive lenses, or [[bifocals]].

			==Correction==
			As you age, the lens in your eye becomes less flexible. This makes [[accommodation]] more difficult and brings on "arms are not long enough to read" symptoms. Someone may be both [[myopic]] and presbyopic, and have deficits in both near and far vision. Your [[Prescription]] will have an "Add" section specifying bifocals or multifocals if you have diagnosed presbyopia, or if your doctor thinks it best to reduce eye strain.

			===Two glasses===
			Having two pairs of glasses, one for close-up, and one for distance, instead of trying to combine both near and far corrections in one pair of glasses, is an option.

			===Bifocals===
			Glasses with a lower section that is specifically for close work.

			===Multifocals===
			Contacts that have sections for near and far work, which the [[visual cortex]] will selectively use when looking at different distances.

	== Measuring ==		== Measuring ==

User at 03:10, 5 February 2022

2022-02-05T03:10:10Z

← Older revision		Revision as of 03:10, 5 February 2022
Line 1:		Line 1:
	Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] or [[bifocals]].		Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]]. This is common in older adults and is commonly treated with [[reading glasses]] (reduced minus for myopes), progressive lenses, or [[bifocals]].

	== Measuring ==		== Measuring ==

User: /* Measuring */

2022-02-05T03:05:23Z

Measuring

← Older revision		Revision as of 03:05, 5 February 2022
Line 15:		Line 15:

	The '''power of accommodation''' is (near power) - (far power). With the first example in each of the above, it would be 10 D - 1.5 D = 8.5 D.		The '''power of accommodation''' is (near power) - (far power). With the first example in each of the above, it would be 10 D - 1.5 D = 8.5 D.

			A person is generally considered to have presbyopia [[wikipedia:if and only if \| iff]] his power of accommodation is less than 2.5 D.

	===Caveats===		===Caveats===

User: /* Caveats */

2022-02-05T03:02:53Z

Caveats

← Older revision		Revision as of 03:02, 5 February 2022
Line 18:		Line 18:
	===Caveats===		===Caveats===

	~~I’m not entirely sure how~~ cylinder ~~affects this measurement~~, ~~so you’ll have to refine the technique~~ if ~~you have cylinder~~.		This technique might need to be refined for cylinder, if spherical equivalent is not used.

	The cornea and lens actually have more power because the total power has to focus the image on your retina, but they cancel out in the subtraction step, so it’s easier to ignore them.		The cornea and lens actually have more power because the total power has to focus the image on your retina, but they cancel out in the subtraction step, so it’s easier to ignore them.

User: /* Measuring */

2022-02-05T03:02:19Z

Measuring

← Older revision		Revision as of 03:02, 5 February 2022
Line 2:		Line 2:

	== Measuring ==		== Measuring ==
	To determine ~~your~~ '''power of accommodation''', ~~you need to~~ measure ~~your~~ '''far power''' and '''near power'''.		To determine '''power of accommodation''', also sometimes called '''amplitude of accommodation''', measure '''far power''' and '''near power'''.

	~~Your~~ '''~~far~~ power''' is straightforward, and it’s the [[cm measurement]]~~s you normally do~~: just measure the furthest distance you can see clearly without blur, with a lens to adjust as needed. The far power is ''1/(distance to blur) - (lens power)''.		'''Far power''' is straightforward, and it’s the typical [[cm measurement]]: just measure the furthest distance you can see clearly without blur, with a lens to adjust as needed. The far power is ''1/(distance to blur) - (lens power)''.

	* For example, 80 cm with a -0.25 lens is calculated as 1/(80 cm) - (-0.25 D) = 1.25 D + 0.25 D = 1.5 D.		* For example, 80 cm with a -0.25 lens is calculated as 1/(80 cm) - (-0.25 D) = 1.25 D + 0.25 D = 1.5 D.
	* It might be useful to use a plus lens to measure low myopia. For example, 80 cm with a +0.75 lens is calculated as 1/(80 cm) - (+0.75 D) = 0.5 D.		* It might be useful to use a plus lens to measure low myopia. For example, 80 cm with a +0.75 lens is calculated as 1/(80 cm) - (+0.75 D) = 0.5 D.

	~~Your~~ '''~~near~~ power''' is the same, but ~~you~~ measure the '''closest''' distance you can see clearly without blur.		'''Near power''' is the same, but measure the '''closest''' distance you can see clearly without blur.

	* For example, if the closest you can see is 10 cm without lenses, it’s calculated as 1/(10 cm) - 0 = 10 D.		* For example, if the closest you can see is 10 cm without lenses, it’s calculated as 1/(10 cm) - 0 = 10 D.

User at 03:01, 5 February 2022

2022-02-05T03:01:07Z

@@ Line 1: / Line 1: @@
 Presbyopia is the hardening of the [[lens]] in the [[eyeballs]] such that it becomes difficult to see [[near work]].  This is common in older adults and is commonly treated with [[reading glasses]] or [[bifocals]].
 {{#ev:vimeo|284921410||inline}}<br/>
@@ Line 6: / Line 28: @@
 {{#ev:youtube|QvmOkVjwPyI||inline}}
-===Other Resources===
+== Resources ==
 [[Category:Articles]]
 [[Category:Eye conditions]]

Angel: /* Other Resources */

2021-12-19T03:19:16Z

Other Resources

← Older revision		Revision as of 03:19, 19 December 2021
Line 8:		Line 8:
	===Other Resources===		===Other Resources===

	Here is a resource that may be of interest to people with presbyopia that was found in the Discord chat. http://www.i-see.org/rizzi_charts_readvertical.pdf		Here is a resource that may be of interest to people with presbyopia that was found in the Discord chat. The resource is used for training convergence. http://www.i-see.org/rizzi_charts_readvertical.pdf
	[[Category:Articles]]		[[Category:Articles]]
	[[Category:Eye conditions]]		[[Category:Eye conditions]]