Accommodation dynamics as a function of age

Gordon Heron, W. N. Charman, Lyle S. Gray

Research output: Contribution to journalArticle

Abstract

Experiments are described in which the dynamic accommodation response to a stimulus whose vergence was varying sinusoidally with time between 1.33 and 2.38 D was measured as a function of frequency for 19 subjects, with ages distributed between 18 and 49 years. Response to abrupt stimulus change between the same levels was also measured. The results showed that at any age, for the sinusoidal stimuli, gain fell with frequency and phase lag increased: at fixed frequency, gain fell with age and phase lag increased. Neither reaction nor response times for step stimuli changed with age. Analysis of the sinusoidal data suggests the possible existence of a cut-off frequency of about 2 Hz, which varies little with age and above which the system cannot respond. The phase data is compatible with the existence of a frequency-independent time delay, which increases with age from about 0.17 s at 20 years to 0.48 s at 40 years. The results are discussed in terms of current knowledge of the factors contributing to the development of presbyopia.

Original languageEnglish
JournalOphthalmic and Physiological Optics
Publication statusPublished - 1 Nov 2002

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Presbyopia
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Keywords

  • ageing
  • vision science
  • presbyopia

Cite this

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title = "Accommodation dynamics as a function of age",
abstract = "Experiments are described in which the dynamic accommodation response to a stimulus whose vergence was varying sinusoidally with time between 1.33 and 2.38 D was measured as a function of frequency for 19 subjects, with ages distributed between 18 and 49 years. Response to abrupt stimulus change between the same levels was also measured. The results showed that at any age, for the sinusoidal stimuli, gain fell with frequency and phase lag increased: at fixed frequency, gain fell with age and phase lag increased. Neither reaction nor response times for step stimuli changed with age. Analysis of the sinusoidal data suggests the possible existence of a cut-off frequency of about 2 Hz, which varies little with age and above which the system cannot respond. The phase data is compatible with the existence of a frequency-independent time delay, which increases with age from about 0.17 s at 20 years to 0.48 s at 40 years. The results are discussed in terms of current knowledge of the factors contributing to the development of presbyopia.",
keywords = "ageing, vision science, presbyopia",
author = "Gordon Heron and Charman, {W. N.} and Gray, {Lyle S.}",
note = "Originally published in: Ophthalmic and Physiological Optics (2002), 22 (5), pp.389-396.",
year = "2002",
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day = "1",
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journal = "Ophthalmic and Physiological Optics",
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Accommodation dynamics as a function of age. / Heron, Gordon; Charman, W. N.; Gray, Lyle S.

In: Ophthalmic and Physiological Optics, 01.11.2002.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Accommodation dynamics as a function of age

AU - Heron, Gordon

AU - Charman, W. N.

AU - Gray, Lyle S.

N1 - Originally published in: Ophthalmic and Physiological Optics (2002), 22 (5), pp.389-396.

PY - 2002/11/1

Y1 - 2002/11/1

N2 - Experiments are described in which the dynamic accommodation response to a stimulus whose vergence was varying sinusoidally with time between 1.33 and 2.38 D was measured as a function of frequency for 19 subjects, with ages distributed between 18 and 49 years. Response to abrupt stimulus change between the same levels was also measured. The results showed that at any age, for the sinusoidal stimuli, gain fell with frequency and phase lag increased: at fixed frequency, gain fell with age and phase lag increased. Neither reaction nor response times for step stimuli changed with age. Analysis of the sinusoidal data suggests the possible existence of a cut-off frequency of about 2 Hz, which varies little with age and above which the system cannot respond. The phase data is compatible with the existence of a frequency-independent time delay, which increases with age from about 0.17 s at 20 years to 0.48 s at 40 years. The results are discussed in terms of current knowledge of the factors contributing to the development of presbyopia.

AB - Experiments are described in which the dynamic accommodation response to a stimulus whose vergence was varying sinusoidally with time between 1.33 and 2.38 D was measured as a function of frequency for 19 subjects, with ages distributed between 18 and 49 years. Response to abrupt stimulus change between the same levels was also measured. The results showed that at any age, for the sinusoidal stimuli, gain fell with frequency and phase lag increased: at fixed frequency, gain fell with age and phase lag increased. Neither reaction nor response times for step stimuli changed with age. Analysis of the sinusoidal data suggests the possible existence of a cut-off frequency of about 2 Hz, which varies little with age and above which the system cannot respond. The phase data is compatible with the existence of a frequency-independent time delay, which increases with age from about 0.17 s at 20 years to 0.48 s at 40 years. The results are discussed in terms of current knowledge of the factors contributing to the development of presbyopia.

KW - ageing

KW - vision science

KW - presbyopia

M3 - Article

JO - Ophthalmic and Physiological Optics

JF - Ophthalmic and Physiological Optics

SN - 0275-5408

ER -