The Dynamic Response of Visual Accommodation Over a Seven – Day Period

Randle, Robert J.; Murphy, M. R.

doi:10.1097/00006324-197408000-00002

Cited by 13 publications

(7 citation statements)

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“…Previous studies have shown that accommodative facility training improves the facility rate at distance and near, as measured both objectively and subjectively (Bobier & Sivak, 1982;Hung, Ciuffreda & Semmlow, 1986;Levine et al, 1985;Liu et al, 1979;Radhakrishnan et al, 2007;Randle & Murphy, 1974). The present study, using 15 minute training sessions on only 3 consecutive days, showed similar levels of improvement in accommodative facility rates in emmetropes and myopes, both at distance and near.…”

Section: Discussionsupporting

confidence: 80%

Changes in dynamics of accommodation after accommodative facility training in myopes and emmetropes

2010

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This study evaluates the effect of accommodative facility training in myopes and emmetropes. Monocular accommodative facility was measured in nine myopes and nine emmetropes for distance and near. Subjective facility was recorded with automated flippers and objective measurements were simultaneously taken with a PowerRefractor. Accommodative facility training (a sequence of 5 min monocular right eye, 5 min monocular left eye, 5 min binocular) was given on three consecutive days and facility was re-assessed on the fifth day. The results showed that training improved the facility rate in both groups. The improvement in facility rates were linked to the time constants and peak velocity of accommodation. Some changes in amplitude seen in emmetropes indicate an improvement in facility rate at the expense of an accurate accommodation response.

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Section: Discussionsupporting

confidence: 80%

Changes in dynamics of accommodation after accommodative facility training in myopes and emmetropes

2010

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“…Dynamic accommodation responses to step inputs, taken only at the completion of training, revealed average latencies and time constants (the time taken to reach 63.2% of the final level in an exponential response) in each eye. The values agreed with those reported in the literature (Randle and Murphy, 1974). Table 2 summarizes our findings.…”

Section: Laboratory Results: Dynamic Accommodationsupporting

confidence: 91%

Orthoptic Effects on Accommodation and Related Visual Functions in an Adult Alternating Esotrope

Schnider

Ciuffreda

Selenow

1985

Ophthalmic Physiologic Optic

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Orthoptic therapy was instituted in an adult, alternating esotrope with asthenopia who exhibited inaccurate static accommodative responses with adequate, clinically determined, accommodative facility. During and following therapy the patient showed considerable improvement in accommodative accuracy and related visual functions, such as contrast sensitivity, in the absence of any change in strabismic deviation. This case provides the first laboratory documentation of orthoptic effects on accommodation in an adult strabismic.

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“…Two of these studies used patients with asthenopia (Liu et al, 1979; Bobier & Sivak, 1983), two used normal subjects (Radhakrishnan et al, 2007; Allen et al, 2010) and one measured the change in accommodation over a one week period with no explicit vision training (Randle & Murphy, 1974). …”

Section: Discussionmentioning

confidence: 99%

“…Randle and Murphy (1974) also tested normal subjects but their subjects received no explicit vision training. They were tested on an SRI optometer every three hours (except for a sleep period) over a period of 7 days.…”

Section: Discussionmentioning

confidence: 99%

Short-term adaptation of accommodation, accommodative vergence and disparity vergence facility

2012

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Previous studies have found that subjects can increase the velocity of accommodation using visual exercises such as pencil push ups, flippers, Brock strings and the like and myriad papers have shown improvement in accommodation facility (speed) and sufficiency (amplitude) using subjective tests following vision training but few have objectively measured accommodation before and after training in either normal subjects or in patients diagnosed with accommodative infacility (abnormally slow dynamics). Accommodation is driven either directly by blur or indirectly by way of neural crosslinks from the vergence system. Until now, no study has objectively measured both accommodation and accommodative-vergence before and after vision training and the role vergence might play in modifying the speed of accommodation. In the present study, accommodation and accommodative-vergence were measured with a Purkinje Eye Tracker/Optometer before and after normal subjects trained in a flipper-like task in which the stimulus stepped between 0 and 2.5 diopters and back for over 200 cycles. Most subjects increased their speed of accommodation as well as their speed of accommodative vergence. Accommodative vergence led the accommodation response by approximately 77 msec before training and 100 msec after training and the vergence lead was most prominent in subjects with high accommodation and vergence velocities and the vergence leads tended to increase in conjunction with increases in accommodation velocity. We surmise that volitional vergence may help increase accommodation velocity by way of vergence-accommodation cross links.

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The Dynamic Response of Visual Accommodation Over a Seven – Day Period

Cited by 13 publications

References 0 publications

Changes in dynamics of accommodation after accommodative facility training in myopes and emmetropes

Changes in dynamics of accommodation after accommodative facility training in myopes and emmetropes

Orthoptic Effects on Accommodation and Related Visual Functions in an Adult Alternating Esotrope

Short-term adaptation of accommodation, accommodative vergence and disparity vergence facility

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