A Yellow Filter Improves Response Times to Low-Contrast Targets and Traffic Hazards

The Effect of Yellow Filter Use on Standard Automated Perimetry and Contrast Sensitivity in Healthy Individuals

Purpose The purpose of this study is to investigate the effect of two yellow filters (category 1: visible light transmission {VLT} from 80% to 43%) of Essilor (Kiros® and Lumior®) on standard automated perimetry (SAP) indices and Pelli-Robson (PR) contrast sensitivity (CS) testing in healthy individuals. Materials and methods This study is a prospective comparative study of 31 eyes of 31 healthy individuals aged 32.14 (8.13) years (14 males and 17 females). All participants underwent a series of three visual field (VF) examinations (24-2, Swedish Interactive Thresholding Algorithm {SITA} standard) with the Humphrey field analyzer (HFA II 740, Carl Zeiss Meditec, Jena, Germany) and three CS examinations with the PR chart (Precision Vision, Inc., Woodstock, IL). VF and CS examinations were carried out as follows: (a) no filter (NF), (b) with the yellow filter Kiros® (KIROS), and (c) with the yellow-orange filter Lumior® (LUMIOR). The effect of the two yellow filters on global VF indices (glaucoma hemifield test {GHT}, mean deviation {MD}, pattern standard deviation {PSD}, and visual field index {VFI}) and on CS score was evaluated and compared. Results When comparing the three pairs NF-KIROS, NF-LUMIOR, and KIROS-LUMIOR, no difference was presented on the global VF indices. However, a statistically significant difference was detected in the CS scores for all three pairs, favoring KIROS. It is important to note that while this difference was statistically significant, it did not reach clinical significance. Conclusions The use of yellow filters (category 1: VLT of 75% and 65%) does not affect the global VF indices and the CS of healthy individuals but significantly improves their CS score. Further studies are required to explore the clinical significance of these findings.

Traumatic brain injury: Mechanisms, manifestations, and visual sequelae

Traumatic brain injury (TBI) results when external physical forces impact the head with sufficient intensity to cause damage to the brain. TBI can be mild, moderate, or severe and may have long-term consequences including visual difficulties, cognitive deficits, headache, pain, sleep disturbances, and post-traumatic epilepsy. Disruption of the normal functioning of the brain leads to a cascade of effects with molecular and anatomical changes, persistent neuronal hyperexcitation, neuroinflammation, and neuronal loss. Destructive processes that occur at the cellular and molecular level lead to inflammation, oxidative stress, calcium dysregulation, and apoptosis. Vascular damage, ischemia and loss of blood brain barrier integrity contribute to destruction of brain tissue. This review focuses on the cellular damage incited during TBI and the frequently life-altering lasting effects of this destruction on vision, cognition, balance, and sleep. The wide range of visual complaints associated with TBI are addressed and repair processes where there is potential for intervention and neuronal preservation are highlighted.

Yellow (Lens) Better: Bioelectrical and Biometrical Measures to Assess Arousing and Focusing Effects

Colours can induce several psychological effects, conditioning perceptions, cognitive/emotional states and human performances. In this exploratory study we investigated the effect of a yellow light exposure, obtained filtering the ambient light with coloured glasses, on the human's psychological functioning. In particular we wanted to assess if people are more able to focus when exposed to a yellow light. We recorded EEG, SC, HR and gaze-related data from 16 subjects (50% split in experimental and control group) during the execution of a reactivity test (the Hazard Perception Test, HPT). Compared with the control group, the experimental group showed increases in concentration, focus, visual attention and arousal, as measured by increases of first fixation duration and Beta over-Alpha ratio (BAR) as well as by decreases of distraction, workload, and number of gaze revisits.

Effects of Intermediate-Tinted Lenses on Pistol Marksmanship and Visual Performance

INTRODUCTION

The standard issue clear or sun Military Combat Eye Protection (MCEP) is often inadequate in visually challenging training or combat environment. Intermediate-tinted lenses may offer a viable option for warfighters operating in dynamic visual conditions such as moving rapidly from bright sunny areas to darker building interiors in combat. Because the use of intermediate-tinted lenses has been delayed as a result of a potential negative impact on vision performance such as color perception, this investigation evaluated several commercially available intermediate-tinted lenses for operation performance during a U.S. military field training. Test lenses complied with all the requirements of the current MCEP except for the visible light transmittance (VLT) values that ranged between 32 and 62%.

MATERIALS AND METHODS

Study subjects consisted of 22 service members who attended a military Close Combat and Marksmanship training course in May 2019. Visual and pistol marksmanship performance of three intermediate-tinted lenses (Eye Safety Systems [ESS] Copper [32% VLT], Oakley Prizm TR45 [44% VLT], and ESS Bronze [62% VLT]) was compared to that of a standard issue MCEP, ESS Clear (90% VLT). Quick contrast sensitivity function test was used to assess quality vision (AULCSF, area under a log contrast sensitivity function) and visual acuity (CSF Acuity). Color vision was assessed by Cone Contrast Test. Pistol marksmanship (Bill Drill) was used for performance testing. A pre-survey inquired about MCEP use, and a MCEP survey during the pistol marksmanship testing inquired about lens performance and ranking.

RESULTS

AULCSF and CSF Acuity were significantly affected by the lenses (general linear model, repeated measures, P < .05). Bonferroni post hoc test showed a significant reduction of binocular AULCSF from ESS Clear to Oakley Prizm TR45 (P = .003) and ESS Copper (P < .001) and a significant reduction in binocular CSF Acuity from ESS Clear to ESS Copper (P = .001). Color vision and pistol marksmanship performance were not significantly affected by wearing different lenses (P > .05). Subjectively, there were no statistically significant differences among study lenses in perceived "clarity of vision," "ability to clearly identify the target," or "overall performance" (Friedman test and Wilcoxon signed-rank post hoc test with Bonferroni adjustment, P > .017). Participants ranked Prizm TR45 (44% VLT) and ESS Bronze (62% VLT) lenses significantly more favorably than EES Clear (P = .001 and P = .009).

CONCLUSIONS

Quality of vision and visual acuity decreased with darker lenses; however, the study lenses had insignificant impacts on pistol marksmanship and subjective acceptance. Our surveys indicated that Intermediate-tinted lenses were operationally acceptable and preferred over a standard issue MCEP. While more evaluations for color vision deficient subjects are needed, overall results suggest that commercially available intermediate-tinted lenses may be a viable option to enhance protection and performance in a visually dynamic combat environment.

Comparison of Pedestrian Detection With and Without Yellow-Lens Glasses During Simulated Night Driving With and Without Headlight Glare

Importance

Some marketing materials for yellow-lens night-driving glasses claim that they increase nighttime road visibility and reduce oncoming headlight glare (HLG). However, there is no scientific evidence to support these claims.

Objective

To measure the association between yellow-lens glasses and the detection of pedestrians with and without an oncoming HLG, using a driving simulator equipped with a custom HLG simulator.

Design, Setting, and Participants

A single-center cohort study was conducted between September 8, 2016, and October 25, 2017, at the Schepens Eye Research Institute. A total of 22 individuals participated in the study, divided into groups to determine response to a pedestrian wearing a navy blue shirt by younger individuals and, to control for participant's age and the interaction of the shirt color with the filter, response to a pedestrian wearing an orange shirt by a group of younger and older participants.

Exposures

Participants drove scripted night-driving scenarios, 3 times with 3 commercially available yellow-lens glasses and once with clear-lens glasses, with the HLG simulator turned on and off. A total of 8 conditions were used for each participant.

Main Outcomes and Measures

Pedestrian detection response time.

Results

The 22 participants who completed the study included 12 younger (mean [SD] age, 28 [7] years; 6 men) individuals who responded to a pedestrian wearing a dark navy blue shirt, as well as 6 younger (mean [SD] age, 27 [4] years; 4 men) and 4 older (mean [SD], 70 [11] years; all men) participants who responded to a pedestrian in an orange shirt. All participants had normal visual acuity (mean [SD], -0.05 [0.06] logMAR). No significant difference in response time with yellow lens was found in all experiment conditions; younger participants for dark navy blue shirt pedestrians (F1,33 = 0.59; P = .45), orange shirt pedestrians (F1,15 = 0.13; P = .72), and older participants for orange shirt pedestrians (F1,9 = 0.84; P = .38). Among all participants (n = 22), no significant main effect of yellow lenses was found (F1,63 = 0.64; P = .42). In all measuring conditions, the response times with the yellow lenses were not better than with the clear lenses. Significant main effects of HLG were found with dark navy blue shirt pedestrian condition for young participants (F1,33 = 7.34; P < .001) and with orange shirt pedestrian condition for older individuals (F1,9 = 75.32; P < .001), where the difference in response time between with and without HLG was larger for older (1.5 seconds) than younger (0.3 seconds) participants.

Conclusions and Relevance

Using a driver simulator equipped with an HLG simulator, yellow-lens night-driving glasses did not appear to improve pedestrian detection at night or reduce the negative effects of HLG on pedestrian detection performance. These findings do not appear to support having eye care professionals advise patients to use yellow-lens night-driving glasses.

Looking Through "Rose-Tinted" Glasses: The Influence of Tint on Visual Affective Processing

The use of color-tinted lenses can introduce profound effects into how we process visual information at the early to late stages. Besides mediating harsh lighting conditions, some evidence suggests that color-tinted lenses can influence how humans respond to emotional events. In this study, we systematically evaluated how color-tinted lenses modified our participants' psychophysiological responses to emotion-inducing images. The participants passively viewed pleasant, neutral or unpleasant images from the International-Affective-Picture-System (IAPS), while wearing none, blue, red, yellow or green tinted-lenses that were controlled for luminance. Established neuroergonomic indices of arousal were measured on the autonomic level, namely Skin-Conductance-Response (SCR) and Heart-Rate-Variability (HRV), and on the cortical level, with electroencephalography (EEG) event-related potentials (ERPs). Phasic SCR responses were significantly enhanced for unpleasant images and both pleasant and unpleasant images induced significantly larger ERP amplitudes of the Late-Positive-Potential (LPP), with pleasant images having the greatest impact. Interestingly, a significant main effect was found for tint. Similar to viewing pleasant images, red-tinted lenses induced the largest LPPs. Taken together, these findings suggest that the autonomic response to affective images is modulated at the cortical level of processing, congruent with the use of red-tinted lenses.

What is Developmental Dyslexia?

Until the 1950s, developmental dyslexia was defined as a hereditary visual disability, selectively affecting reading without compromising oral or non-verbal reasoning skills. This changed radically after the development of the phonological theory of dyslexia; this not only ruled out any role for visual processing in its aetiology, but it also cast doubt on the use of discrepancy between reading and reasoning skills as a criterion for diagnosing it. Here I argue that this theory is set at too high a cognitive level to be explanatory; we need to understand the pathophysiological visual and auditory mechanisms that cause children's phonological problems. I discuss how the 'magnocellular theory' attempts to do this in terms of slowed and error prone temporal processing which leads to dyslexics' defective visual and auditory sequencing when attempting to read. I attempt to deal with the criticisms of this theory and show how it leads to a number of successful ways of helping dyslexic children to overcome their reading difficulties.