The use of cues to convergence and accommodation in naïve, uninstructed participants

Horwood, Anna M.; Riddell, Patricia M.

doi:10.1016/j.visres.2008.04.023

Cited by 58 publications

(104 citation statements)

References 73 publications

(88 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In our laboratory we find that very few people actually clear induced blur completely, even to a detailed target, and many seem very happy with what must be significant blur for detailed targets. 9 Even when given a demanding task such as to N5 text, accommodative responses may still be less than we would expect. 10 Very different clinical response patterns can also produce identical response ratios.…”

Section: Introductionmentioning

confidence: 80%

“…We can measure accommodation and convergence simultaneously and naturalistically, and we can manipulate blur, disparity and proximal/looming cues independently to show how each drives responses when presented in isolation, and also how removing the same cue degrades responses when the other two remain. 9 We have also looked at the development of cue use across the lifespan, from prematurity to middle age.…”

Section: Ratios or Cues?mentioning

confidence: 99%

“…In adults and children over 5 years of age, disparity is by far the strongest cue, with blur and proximal cues being much weaker, so disparity fiCfiCA linkages are more influential than blurfiA fiAC. 9 Infants and young children are very different. We studied 45 infants over their first year to explore developmental changes in cue use.…”

Section: Typical Developmentmentioning

confidence: 99%

See 2 more Smart Citations

Convergence accommodation in orthoptic practice

Horwood

2016

British and Irish Orthoptic Journal

View full text Add to dashboard Cite

Aim: Orthoptists are familiar with AC/A ratios and the concept that accommodation drives convergence, but the reverse relationship, that of the accommodation associated with convergence, is rarely considered. Methods: This article reviews published evidence from our laboratory which has investigated the drives to both vergence and accommodation. All studies involved a method by which accommodation and vergence were measured concurrently and objectively to a range of visual stimuli which manipulate blur, disparity and proximal/looming cues in different combinations. Results: Results are summarised for both typical and atypical participants, and over development between birth and adulthood. Conclusions: For the majority of typical children and adults, as well as patients with most heterophorias and intermittent exotropia, disparity is the main cue to both vergence and accommodation. Thus the convergence fiaccommodation relationship is more influential than that of accommodative vergence. Differences in 'style' of near cue use may be a more useful way to think about responses to stimuli moving in depth, and their consequences for orthoptic patients, than either AC/A or CA/C ratios. The implications of a strong role for vergence accommodation in orthoptic practice are considered.

show abstract

Section: Introductionmentioning

confidence: 80%

Section: Ratios or Cues?mentioning

confidence: 99%

Section: Typical Developmentmentioning

confidence: 99%

See 1 more Smart Citation

Convergence accommodation in orthoptic practice

Horwood

2016

British and Irish Orthoptic Journal

View full text Add to dashboard Cite

show abstract

“…Other subjective methods use a phoropter or a focometer 2 and objective methods include dynamic retinoscopy, 3 or using a Hartinger coincidence refractometer 2 or a remote Haploscopic Videorefractor incorporating a PlusoptiX SO4. 4 The near point of accommodation is the point nearest the subject that can be seen clearly 5 and it can be measured in two different ways using the RAF rule, both of which rely on accurate and reliable subjective responses. The conventional push-up method has been used for over a century, 6 during which a clear target is gradually moved closer to the subject until they report the point at which the target starts to blur.…”

Section: Introductionmentioning

confidence: 99%

A comparison of the conventional and modified push-up methods of measuring the near point of accommodation

Esmail¹,

Arblaster

2016

British and Irish Orthoptic Journal

View full text Add to dashboard Cite

Aim: To compare the subjective near point of accommodation measurement with the RAF rule using the conventional (clear to blur) and modified (blur to clear) push-up methods. Methods: Both methods of testing the near point of accommodation were carried out uniocularly and binocularly in 32 visually normal participants (mean age: 20.08) with a range of visual experience. Results: The modified push-up method (blur to clear) gave a near point of accommodation further away from the subject. A difference of 0.51 cm in the right eye, 0.61 cm in the left eye and 1.05 cm binocularly was found between the two methods which was statistically significant ( p < 0.05). No difference was found between naïve and expert groups ( p < 0.05). However, most participants reported that the end point was easier to judge with the modified method. Conclusion: Despite being significantly different statistically, the difference between the two methods measuring the near point of accommodation with the RAF rule was small. The findings support the use of the modified method of measuring the near point of accommodation with the RAF rule, rather than the conventional method.

show abstract

“…This perceptual conflict is a main cause of visual discomfort. As the binocular disparity signal is the primary cue in evoking vergence [23], extracting accuracy disparity signals from stereoscopic image pairs is the first important step to make good predictions of the degree of visual discomfort experienced when viewing 3D images.…”

Section: Introductionmentioning

confidence: 99%

3D visual discomfort prediction using low complexity disparity algorithms

Chen

Zhou

Sun

et al. 2016

J Image Video Proc.

View full text Add to dashboard Cite

Algorithms that predict the degree of visual discomfort experienced when viewing stereoscopic 3D (S3D) images usually first execute some form of disparity calculation. Following that, features are extracted on these disparity maps to build discomfort prediction models. These features may include, for example, the maximum disparity, disparity range, disparity energy, and other measures of the disparity distribution. Hence, the accuracy of prediction largely depends on the accuracy of disparity calculation. Unfortunately, computing disparity maps is expensive and difficult and most leading assessment models are based on features drawn from the outputs of high complexity disparity calculation algorithms that deliver high quality disparity maps. There is no consensus on the type of stereo matching algorithm that should be used for this type of model. Towards filling this gap, we study the relative performances of discomfort prediction models that use disparity algorithms having different levels of complexity. We also propose a set of new discomfort predictive features with good performance even when using low complexity disparity algorithms.

show abstract

The use of cues to convergence and accommodation in naïve, uninstructed participants

Cited by 58 publications

References 73 publications

Convergence accommodation in orthoptic practice

Convergence accommodation in orthoptic practice

A comparison of the conventional and modified push-up methods of measuring the near point of accommodation

3D visual discomfort prediction using low complexity disparity algorithms

Contact Info

Product

Resources

About