Positive and negative polarity contrast sensitivity measuring app

Hwang, Alex D.; Peli, Eli

doi:10.2352/issn.2470-1173.2016.16.hvei-122

Cited by 10 publications

(12 citation statements)

References 26 publications

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“…The contrast sensitivities in negative and positive polarity for normal vision subjects were 1.91 ± 0.02 and 1.65 ± 0.01 LogCS, and for the real cataract patients, they were 1.71 ± 0.01 and 1.09 ± 0.01 LogCS, respectively ( Figure 7D ). Similar results were also reported in our previous studies ( Hwang and Peli, 2015 , 2016 ), where the visual acuity was not significantly affected by polarity of the presented letter, but the contrast sensitivity was significantly affected (contrast sensitivity is reduced when measured in positive polarity).…”

Section: Resultssupporting

confidence: 92%

“…Before nighttime driving performance measurements, the visual acuity and contrast sensitivity of each participant was measured with our mobile visual acuity and contrast sensitivity measuring smart phone app ( Hwang and Peli, 2016 ), which enables us to measure visual acuity and contrast sensitivity in positive contrast polarity (a bright letter on dark background). The luminance for the dark background of the contrast sensitivity and visual acuity measuring app was 0.39 cd/m 2 .…”

Section: Methodsmentioning

confidence: 99%

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Impact of Oncoming Headlight Glare With Cataracts: A Pilot Study

et al. 2018

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Purpose: Oncoming headlight glare (HLG) reduces the visibility of objects on the road and may affect the safety of nighttime driving. With cataracts, the impact of oncoming HLG is expected to be more severe. We used our custom HLG simulator in a driving simulator to measure the impact of HLG on pedestrian detection by normal vision subjects with simulated mild cataracts and by patients with real cataracts.Methods: Five normal vision subjects drove nighttime scenarios under two HLG conditions (with and without HLG: HLGY and HLGN, respectively), and three vision conditions (with plano lens, simulated mild cataract, and optically blurred clip-on). Mild cataract was simulated by applying a 0.8 Bangerter diffusion foil to clip-on plano lenses. The visual acuity with the optically blurred lenses was individually chosen to match the visual acuity with the simulated cataract clip-ons under HLGN. Each nighttime driving scenario contains 24 pedestrian encounters, encompassing four pedestrian types; walking along the left side of the road, walking along the right side of the road, crossing the road from left to right, and crossing the road from right to left. Pedestrian detection performances of five patients with mild real cataracts were measured using the same setup. The cataract patients were tested only in HLGY and HLGN conditions. Participants’ visual acuity and contrast sensitivity were also measured in the simulator with and without stationary HLG.Results: For normal vision subjects, both the presence of oncoming HLG and wearing the simulated cataract clip-on reduced pedestrian detection performance. The subjects performed worst in events where the pedestrian crossed from the left, followed by events where the pedestrian crossed from the right. Significant interactions between HLG condition and other factors were also found: (1) the impact of oncoming HLG with the simulated cataract clip-on was larger than with the plano lens clip-on, (2) the impact of oncoming HLG was larger with the optically blurred clip-on than with the plano lens clip-on, but smaller than with the simulated cataract clip-on, and (3) the impact was larger for the pedestrians that crossed from the left than those that crossed from the right, and for the pedestrians walking along the left side of the road than walking along the right side of the road, suggesting that the pedestrian proximity to the glare source contributed to the performance reduction. Under HLGN, almost no pedestrians were missed with the plano lens or the simulated cataract clip-on (0 and 0.5%, respectively), but under HLGY, the rate of pedestrian misses increased to 0.5 and 6%, respectively. With the optically blurred clip-on, the percent of missed pedestrians under HLGN and HLGY did not change much (5% and 6%, respectively). Untimely response rate increased under HLGY with the plano lens and simulated cataract clip-ons, but the increase with the simulated cataract clip-on was significantly larger than with the plano lens clip-on. The contrast sensitivity with the simulated cata...

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Section: Resultssupporting

confidence: 92%

Section: Methodsmentioning

confidence: 99%

Impact of Oncoming Headlight Glare With Cataracts: A Pilot Study

et al. 2018

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“…It is known that negative polarity induces a higher disability glare than positive polarity. Furthermore, binocular vision will have a better contrast sensitivity due to the summation of the CS value [11] .…”

Section: Discussionmentioning

confidence: 99%

Beyond Pseudo-Accomodative Cornea Lasik (Pac Lasik). A Personal Insight

Gondhowiardjo¹,

PhD²

2021

IJCR

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Laser in-situ keratomieleusis (LASIK) is a common intervention for young, active, ametropic individuals to improve their visual acuity. pseudo-accommodative cornea (PAC), a variant of LASIK, to correct ametropia among presbyopic patients is proven in maintaining good distant vision; yet, the satisfactory spectacle free reading vision is limited to the ageing progression. However, successful treatments do not guarantee patient’s satisfaction. Assesment of the objective topographic indicators, visual acuity, higher order abrasion, and contrast sensitivity; revealed the clarification of a mild headache as a personal subjective experience after the treatment. The role of the persistent, dominant eye, the brain perception, seems to be critical factor to a patient’s satisfaction. To a certain degree, the interplay amongst the optical part and it’s supporting tissue, within and between the eyeballs, as well as its relationship to the neurosensory parts of the visual systems after Lasik surgery have not yet been assessed and reported elsewhere.

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“…Lots of apps for various purposes was created in ophthalmology expanding the application of smartphone [32]. As an intelligent terminal with high-resolution and high-brightness screen, visual acuity [33], color vision [34], and contrast sensitivity [35] could be tested precisely. As a high performance computer, it can serve to calculate IOL power [36], refractive error [37], or the grading of diabetic retinopathy [38].…”

Section: Discussionmentioning

confidence: 99%

Screening for Stereopsis of Children Using an Autostereoscopic Smartphone

Yang

2019

Journal of Ophthalmology

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Background The advantage of using an autostereoscopic smartphone is that it can achieve 3D effects without the need for glasses. The purpose of this study was to evaluate whether this technology could be utilized to detect stereoacuity. Methods An autostereoscopic smartphone was used to imitate Lang stereotest I & II, Pass Test 3, Dinosaur Stereoacuity Test, and the Random Dot Stereo Acuity Test to screen the stereopsis of children from 3–6 years old. Results No significant difference was found between each pair of groups (autostereoscopic smartphone vs. Lang stereotest I, Lang stereotest II, Pass Test 3, Dinosaur Stereoacuity Test, and Random Dot Stereo Acuity Test, respectively; Wilcoxon signed-rank test, P value all >0.05). All of the weighted kappa were higher than 0.84. Therefore, all of the comparisons between measurements showed a high level of agreement. Conclusions The autostereoscopic smartphone is an effective tool when used for the screening of deficiency in stereopsis.

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Positive and negative polarity contrast sensitivity measuring app

Cited by 10 publications

References 26 publications

Impact of Oncoming Headlight Glare With Cataracts: A Pilot Study

Impact of Oncoming Headlight Glare With Cataracts: A Pilot Study

Beyond Pseudo-Accomodative Cornea Lasik (Pac Lasik). A Personal Insight

Screening for Stereopsis of Children Using an Autostereoscopic Smartphone

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