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A person with hyperopia has a near point that is further away than the typical near point for someone their age, and hence the person is unable to bring an object at the typical near point distance into sharp focus. A
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A normal eye is considered to have a near point at about 11 cm (4.3 in) for a thirty year old. The near point is highly age dependent (see
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This article is about a measure of an individual's ability to see close (near) objects as clear and in focus. For the near point of convergence, see
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2018 40th Annual
International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
77:), which refers to the inverse of the distance. For example a normal eye would have a near point of
305:{\displaystyle P={\frac {1}{D-0.015\;{\text{m}}}}-{\frac {1}{{\mathit {NP}}-0.015\;{\text{m}}}}.}
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can be used to correct hyperopia by imaging an object at the typical near point distance
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The calculation can be further improved by taking into account the distance between the
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472:"Estimation of Spherical Refractive Errors Using Virtual Reality Headset"
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is the closest point at which an object can be placed and still form a
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213:{\displaystyle P\approx {\frac {1}{D}}-{\frac {1}{\mathit {NP}}}.}
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121:{\displaystyle {\frac {1}{11\ {\text{cm}}}}=9\ {\text{diopters}}}
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Goyal, Ashish; Bopardikar, Ajit; Tiwari, Vijay
Narayan (2018).
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range. The other limit to the eye's accommodation range is the
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and the human eye, which is usually about 1.5 cm:
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would have a near point that is farther than normal.
478:. Vol. 2018. Honolulu, HI: IEEE. p. 4976.
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and the typical near point distance at their age is
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149:at the patient's actual near point, at distance
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366:American Journal of Ophthalmology
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157:, the required lens will have
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447:"Vision Correction | Physics"
378:10.1016/s0002-9394(22)90793-7
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314:For example, if a person has
540:. You can help Knowledge by
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75:Presbyopia § Mechanism
18:Vergence § Convergence
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484:10.1109/EMBC.2018.8513209
451:courses.lumenlearning.com
360:Duane, Alexander (1922).
399:Keeports, David (2016).
532:This article about the
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401:"Fix your own vision"
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405:The Physics Teacher
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333:= +3.24 diopters
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372:(11): 865–877.
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153:. From the
581:Categories
456:2019-12-05
347:References
341:reciprocal
335:where one
64:presbyopia
29:near point
592:Eye stubs
433:0031-921X
285:−
266:−
251:−
190:−
177:≈
164:given by
60:hyperopia
49:far point
510:53106585
502:30441458
386:43172462
115:diopters
71:diopters
413:Bibcode
339:is the
337:diopter
326:= 25 cm
145:onto a
33:focused
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37:retina
27:, the
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