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

Key Points

Question

Are yellow-lens night-driving glasses associated with increases in nighttime road visibility and reductions in headlight glare from oncoming vehicles?

Findings

In this cohort study of 22 individuals, yellow-lens night-driving glasses did not appear to improve pedestrian detection at night or reduce the negative association between headlight glare and pedestrian detection performance. A difference in detection with the yellow lenses was not noted based on pedestrian shirt color.

Meaning

These findings do not appear to support having eye care professionals advise patients to use yellow-lens night-driving glasses.

Abstract

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 (F_1,33 = 0.59; P = .45), orange shirt pedestrians (F_1,15 = 0.13; P = .72), and older participants for orange shirt pedestrians (F_1,9 = 0.84; P = .38). Among all participants (n = 22), no significant main effect of yellow lenses was found (F_1,63 = 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 (F_1,33 = 7.34; P < .001) and with orange shirt pedestrian condition for older individuals (F_1,9 = 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.

This cohort study examines the use of yellow-lens glasses for detection of pedestrians during night driving by younger and older individuals.

Introduction

Yellow-lens night-driving glasses have been commercially available for many years, and the effectiveness of such glasses has been discussed since the early 1950s.^1,2,3 Advertisements on television, the internet, and in print frequently claim that night-driving glasses improve night visibility and reduce the negative effects of headlight glare (HLG).

Some distributors of the night-driving glasses describe specific performance improvements, such as “filter out high-intensity glare from oncoming headlights, street lights, and illuminated billboards”⁴; “enhancing clarity and visual acuity for night driving”⁴; “enhanced visual definition and contrast”⁴;“improves your ability to detect and distinguish objects”⁴; “cuts glare, makes things brighter, and enhances contrast and clarity”⁵; and “gives you instant visual clarity by significantly reducing glare at night.”⁶

Yellow-lens night-driving glasses continue to be sold and advertised with such benefits despite a 1997 ruling by the Federal Trade Commission against the Nationwide Syndications Inc on the NightSafe night glare-reducing glasses.⁷ This ruling prohibited advertising directly or by implication that the product improves night vision or makes night driving safer and imposed a fine on the company. The ruling stated that the claims were not backed up by sufficient evidence but did not conclude that the yellow-lens night-driving glasses were in fact ineffective.

A 1972 study⁸ measured the performance of yellow filters compared with neutral filters on contrast detection thresholds for different background and target chromatic combinations. The study found that the threshold increases (performance decreases) more with yellow filters than with neutral filters. The findings also reported that the threshold increases as the wavelength of the background increases, as the target size reduces, and as the overall luminance decreases. The study also found that the threshold increase with yellow filters is lowered as the observer’s age increases, suggesting that natural yellowing of the aging lens might reduce the negative influence of an external yellow filter.

A 1965 publication³ reviewed studies on night driving and the use of yellow filters and found that the yellow filters negatively affect visual function (mostly visual acuity [VA]) under low light conditions. A 1954 study¹ measured the association between yellow filters and visual detection in low luminance conditions with and without a glare source and found that yellow filters increased the target size detection threshold by approximately 27% compared with the threshold without any glasses in all contrast conditions. The filters were more deleterious for visual detection when glare was presented (32%).

In 1951, a study⁹ measured VA with and without a glare source with 44 varieties of filters with various color and transmittance levels. Visual acuity was worsened in all color conditions with and without presence of glare. For some colors and transmittance levels, the glare effect (worsening of VA in the presence of glare) was reduced. However, because VA was worsened both with and without the filtered lenses in these conditions, the investigator concluded that any media between the eye and an object is not recommended, especially for night driving where maximum visual efficiency is desired.

Yellow lenses filter out shorter-wavelength light and reduce the overall light level; both actions may reduce the subjective discomfort caused by bright, oncoming HLG.^10,11 Discomfort glare is found to be a U-shape function of wavelength, where yellow light (577 nm) induced minimum discomfort,¹⁰ but this discomfort glare is not related to disability glare.¹¹ We found no data that directly support claims that the yellow lenses improve road visibility or increase safety when driving at night with or without HLG.

A video-based daylight driving hazard perception study reported that the response time was shortened by a yellow filter.¹² The relevance of this finding to our study is minimal. However, also in that study, no main effect of yellow lenses was found in the hazard detection or the contrast sensitivity experiments.

Our custom HLG simulator¹³ installed in a driving simulator allowed measurement of the association between HLG and the visibility of pedestrians crossing or walking along the road even for younger healthy drivers as well as older drivers.¹⁴ The negative response to HLG was larger for older drivers with incipient cataracts.¹⁴ Pedestrian detection is particularly relevant to night driving because crash involvement for nonreflective pedestrians and animals increases up to 7 times in lower lighting settings,¹⁵ and most pedestrian actions in fatal crashes are improper road crossings and walking along the side of the road.^16,17,18

With this system, we compared the utility of 3 commercially available yellow-lens night-driving glasses with clear lenses for pedestrian detection performance of younger and older drivers with and without HLG.

Methods

Yellow-Lens Night-Driving Glasses

Three commercially available night-driving glasses were selected to be tested: Night-Lite (Eagle Eyes Optics), HD Night Vision (Idea Village Co), and Knight Visor (Blupond Inc). All 3 night-driving glasses were equipped with yellow lenses. All lenses were confirmed to be plano and free of scratches or manufacturing blemishes.

Figure 1 shows the spectral characteristics of the 3 yellow-lens glasses as well as the emission power spectrum of the white, high-power, light-emitting diode (LED) used in the HLG simulator (NSPW500DS; Nichia Corp). Similar high-intensity LEDs of 4100K or 5000K color temperature are often used for vehicle headlights, and those headlights have a similar power spectral peak at 400 to 500 nm.^19,20,21 Spectral characteristics of the 3 yellow-lens glasses were measured by a spectrophotometer (Evolution 220; Thermo Fisher Scientific Inc). The transmittance of all 3 yellow-lens glasses has similar characteristics; most long-wavelength lights are transmitted through the lens and shorter-wavelength lights are blocked by the lens. The LED’s spectral peak is within the transition range and mostly attenuated by the yellow lenses. The power spectral distribution of the LED is from the manufacturer’s specifications.²²

Figure 1. Spectral Characteristics of the Yellow Lenses Evaluated and Light-emitting Diode (LED) (NSPW500DS) Used for Headlight Glare Simulation.

Left axis indicates the transmittance of the yellow lens and right axis indicates relative light emission intensity; au indicates arbitrary unit. The LED spectral power peak in the short wavelength (blue) range is common in LEDs used for car headlights and is attenuated by more than half by all 3 glasses.

Driving Simulator and HLG Simulation

The LE-1500 driving simulator (FAAC Inc) has five 42-inch LCD monitors covering a field of view of 225°H × 37°V. Data from the driving simulator include position, speed, steering angle, and heading of the participant’s vehicle and all scripted entities (other vehicles and pedestrians), as well as horn press.

We developed a custom HLG simulator¹³ that provides a realistic and dynamic simulation of the HLG from oncoming cars. Real headlight brightness can be more than 10 000 cd/m²; therefore, the driving simulator screen itself cannot realistically simulate the brightness of oncoming HLG. Our HLG simulator overcomes this limitation by incorporating a high-intensity LED array that can match the brightness of real-world headlights.¹³ Using a beam splitter, the LED light is superimposed over the driving simulator’s screen and moves with the oncoming car in the virtual world. The brightness levels of the LEDs are calibrated to match the real-world headlight’s brightness and adjusted in real-time to account for the relative position between the 2 vehicles.

Procedure

This single-center study was conducted from September 8, 2016, to October 25, 2017. The study was approved by the Massachusetts Eye and Ear Infirmary Institutional Review Board and carried out in accordance with the ethical principles for medical research involving humans. All participants gave written informed consent in accordance with the Declaration of Helsinki.²³ Participants received financial compensation.

All participants completed a total of 8 night driving scenarios, each lasting about 10 minutes, wearing 4 glasses (clear and the 3 products used), with the HLG simulator turned on (HLGY) and off (HLGN). Before beginning the test scenarios, all participants finished 1 or 2 introductory drives, which provided ample time to become accustomed to the driving simulator environment, driving in the simulator, and the experimental tasks. Data collection was done in 2 sessions scheduled on different days. The order of HLG presentation and glasses conditions was counterbalanced within as well as between participants.

Participants were instructed to press the horn as soon as they detected a pedestrian. As an oncoming car approached from 120 m away at 30 mph toward the participant’s car, a pedestrian wearing blue jeans and a dark navy blue shirt appeared on the left or right side of the road 60 m from the participant’s car. The pedestrian then either walked along the side of the road in the same direction as the participant or crossed the road between the 2 cars. Each scenario contained 30 events, including 6 null-pedestrian encounters (ie, with an oncoming car but no pedestrian). Further details of the scenario design can be found in a previous report.¹⁴

With yellow filters, the dark navy blue shirt and blue jeans may be less visible to drivers, forcing them to rely on other parts of the pedestrian (eg, face, hands). To control for this possibility, 6 additional younger individuals completed the same 8 drives; however, the pedestrian wore an orange shirt. It might be expected that detection of pedestrians in the orange shirt would be less affected by the yellow filters. Four older participants’ detection of pedestrians wearing the orange shirt was also measured. Older individuals are more likely to be users of night-driving glasses because they report night-driving difficulties with oncoming car’s HLG owing to incipient cataracts¹⁴ or other age-related eye diseases and may be searching for a method to improve their night-driving comfort and safety.

Participants

A total of 22 individuals were enrolled in the study and divided into 3 groups: 1 younger group for the main experiment, 1 younger group for shirt color comparison, and 1 older group for age comparison.

Table 1 and Table 2 present the mean binocular VA and contrast sensitivity (CS) of the 3 participant groups. Visual acuity and CS were measured once under office lighting with negative contrast polarity letters (dark letters on bright background), and again in the driving simulator in a dark room with positive contrast polarity letters (bright letters on darker background) with and without the HLG simulator turned on. In office lighting, VA was measured (Test Chart 2000 Pro; Thomson Software Solutions) from a 6-m viewing distance, and CS was measured with the Pelli-Robson chart from 90-cm viewing distance. For vision measures in the driving simulator, our VA/CS measuring smartphone app^24,25 was used from approximately 70-cm viewing distance with and without a stationary HLG source. The stationary glare source simulated a car parked 60 m away in the opposite car lane. The individual viewing distance in the driving simulator varied slightly because each participant adjusted the seat to a comfortable driving position. The measuring app allows us to enter an individual viewing distance.

Table 1. Mean Visual Acuity of Participant Groups Under Various Measurement Conditions.

Cohort	Darkroom Condition in Driving Simulator, Visual Acuity, logMAR, Mean (SD) [Snellen Equivalent]a									Office Room Lighting
	Without HLG					With HLG
	Clear	Y1	Y2	Y3	Clear		Y1	Y2	Y3
12 Younger participants in main experiment	−0.05 (0.06) [20/17.8]	−0.06 (0.03) [20/17.4]	−0.05 (0.04) [20/17.8]	−0.07 (0.04) [20/17.0]	−0.07 (0.03) [20/17.0]		−0.05 (0.07) [20/17.8]	−0.05 (0.07) [20/17.8]	−0.06 (0.04) [20/17.4]	−0.06 (0.05)
6 Younger participants in shirt color control	−0.06 (0.02) [20/17.4]	−0.06 (0.05) [20/17.4]	−0.01 (0.07) [20/19.5]	20/18.2/−0.04 (0.08)	−0.07 (0.03) [20/17.0]		−0.09 (0.02) [20/16.3]	−0.09 (0.02) [20/16.3]	−0.07 (0.02) [20/17.0]	0.00 (0.16)
4 Older participants in age control	−0.04 (0.08) [20/18.2]	−0.05 (0.05) [20/17.8]	+0.01 (0.07) [20/20.5]	20/18.7/−0.03 (0.13)	−0.01 (0.13) [20/19.5]		+0.01 (0.08) [20/20.5]	+0.01 (0.08) [20/20.5]	+0.03 (0.11) [2/25]	+0.01 (0.13)

Abbreviation: HLG, headlight glare.

^aY1, Y2, and Y3 indicate the 3 yellow-lens products evaluated.

Table 2. Mean Contrast Sensitivity of Participant Groups Under Various Measurement Conditions.

Cohort	Darkroom Condition in the Driving Simulator, Contrast Sensitivity, logCS, Mean (SD)a								Office Room Lighting
	Without HLG				With HLG
	Clear	Y1	Y2	Y3	Clear	Y1	Y2	Y3
12 Younger participants in main experiment	1.70 (0.20)	1.66 (0.12)	1.70 (0.18)	1.69 (0.11)	1.57 (0.11)	1.57 (0.12)	1.46 (0.10)	1.48 (0.14)	1.90 (0.12)
6 Younger participants in shirt color control	1.85 (0.18)	1.75 (0.12)	1.83 (0.18)	1.80 (0.13)	1.68 (0.11)	1.70 (0.15)	1.58 (0.13)	1.60 (0.18)	1.93 (011)
4 Older participants in age control	1.39 (0.08)	1.20 (0.17)	1.16 (0.14)	1.31 (0.14)	1.05 (0.30)	0.90 (0.30)	0.94 (0.08)	0.98 (0.09)	1.73 (0.09)

Abbreviation: HLG, headlight glare.

^aY1, Y2, and Y3 indicate the 3 yellow-lens products evaluated.

Statistical Analysis

A repeated-measures analysis of variance of the response times was computed to determine whether there is any performance difference among the yellow-lens glasses on both HLG conditions. For our main analysis, a repeated-measures analysis of variance was computed to find out whether there is any performance difference between clear and average yellow glasses. For pedestrian shirt color and age association with the response time change, an unpaired t test was applied to each HLG condition. All significance testing was 2-tailed, and a P value ≤.05 was considered to indicate statistical significance. SPSS Statistics, version V.25 (IBM) was used in the analysis.

Results

Of the 22 participants, 12 younger individuals (mean [SD] age, 28 [7] years; 6 men) were included in the measure of response to a pedestrian wearing blue jeans and a dark navy blue shirt. Six additional younger individuals (mean [SD] age, 27 [4] years; 4 men) participated in the color control experiment with the orange shirt. Four older persons (mean [SD] age, 70 [11] years; all men) were enrolled to examine the response by older age. No significant difference in mean VA was found between the younger groups who participated in the navy blue and orange shirt experiments (t₁₆ = 2.1; P = .33), and between the younger and older groups who participated in the orange shirt experiments (t₈ = 2.3; P = .29). No significant difference in mean CS was found between the 2 younger groups (t₁₆ = 2.1; P = .62), but a significant difference was found between the younger and older groups (t₈ = 2.3; P = .02). All participants had normal VA (mean [SD], -0.05 [0.06] logMAR [20/17.8 Snellen equivalent]).

Pedestrian Response Times With Yellow Lenses

A repeated-measures analysis of variance (2 HLG conditions ×3 yellow-lens glasses conditions) of the response times found no significant main effect of the 3 yellow-lens glasses in all groups and experimental conditions; for 12 younger participants with the navy blue shirt pedestrian (F_2,55 = 0.06; P = .94), for 6 younger participants with the orange shirt pedestrian (F_2,25 = 0.28; P = .75), and for 4 older participants with the orange shirt pedestrian (F_2,15 = 0.02; P = .98). Significant main effects of HLG were found for 12 younger participants with the navy blue shirt pedestrian (F_1,55 = 12.71; P < .001) and for 4 older participants with the orange shirt pedestrian (F_1,15 = 81.24; P < .001), but not for 6 younger individuals with the orange shirt pedestrian (F_1,25 = 3.30; P = .08). No significant interaction between HLG and a particular brand of yellow-lens glasses was found in all groups. Post hoc analysis for both HLG conditions also found no significant difference among the 3 yellow-lens glasses (the eAppendix in the Supplement provides details). Because no performance difference was found among the 3 yellow-lens glasses, in the rest of analysis, the measurements of 3 yellow-lens glasses were averaged to compare their performances with the clear lenses.

Response Times With Clear- vs Yellow-Lens Glasses

Figure 2A compares the response times of the 12 younger participants to a pedestrian wearing a navy blue shirt between clear- and yellow-lens glasses, with and without HLG. A repeated-measures analysis of variance (2 glasses conditions ×2 HLG conditions) found no main effect of glasses (F_1,33 = 0.59; P = .45), although the response times with yellow lenses were longer in all conditions. A significant difference in response time with HLG was found (F_1,33 = 7.34; P < .001), where response times were longer with HLG than without. There was no significant interaction (F_1,44 = 4.06; P = .83).

Figure 2. Distributions of Response Times for Detection of a Pedestrian.

Wearing a navy blue shirt (12 younger participants) (A), wearing an orange shirt (6 younger participants) (B), and wearing an orange shirt (4 older participants) (C). All participants drove the scenarios with and without headlight glare (HLG) wearing clear and all 3 yellow-lens night-driving glasses. No significant main association of yellow lenses was found. Yet, the mean response time was slightly longer with the yellow lenses in all conditions. In most conditions, mean response times were significantly longer with HLG than without HLG. The association with HLG is greater for older participants. The open square in each box and whisker plot represents a mean response time, and the open circle represents an outlier (ie, lies outside of 1.5 times the interquartile range). The P value for comparison between 2 categories (ie, with and without HLG) indicates interactions.

Figure 2B compares the response times of the 6 younger participants to the pedestrian wearing an orange shirt. The repeated-measures analysis of variance (2 glasses conditions ×2 HLG conditions) found no main effect of glasses condition (F_1,15 = 0.13; P = .72) and HLG condition (F_1,15 = 2.82; P = .11), and no interaction (F_1,20 = 0.12; P = .73). Here too, the response times with yellow lenses were longer.

Between-participant comparisons of the response times (unpaired t tests) to the navy blue shirt and orange shirt pedestrians found no significant difference with clear-lens glasses for both HLGN (t₁₆ = 0.63; P = .54) and HLGY (t₁₆ = 0.08; P = .93) and with yellow-lens glasses for both HLGN (t₁₆ = 0.18, P = .86) and HLGY (t₁₆ = 0.57; P = .58). The response time difference between under HLGY and HLGN was also not significantly different with clear-lens (t₁₆ = 0.28; P = .79) and yellow-lens (t₁₆ = 0.66; P = .52) glasses.

Figure 2C compares the response times of the 4 older participants to the virtual pedestrian in the orange shirt with the 6 younger participants’ response time. A repeated-measures analysis of variance (2 glasses conditions ×2 HLG conditions) found no main effect of glasses (F_1,9 = 0.84; P = .38), a significant main effect of HLG with longer response times under HLGY (F_1,9 = 75.32; P < .001), and no interaction (F_1,12 = 0.12; P = .74). Here too, the response times with yellow lenses were longer. Between-participant comparison of the response times (unpaired t tests) for detection of the same pedestrian by younger (Figure 2B) and older (Figure 2C) participants found no difference under HLGN both with clear-lens (t₈ = 0.94; P = .37) and yellow-lens (t₈ = 1.37; P = .21) glasses, but did find significantly increased response times for older participants under HLGY both with clear-lens (t₈ = 4.01; P < .001) and yellow-lens (t₈ = 5.92; P < .001) glasses. The association between response time and HLG was found to be larger for older participants both with clear lenses (t₈ = 5.78; P < .001) and yellow lens (t₈ = 11.73; P < .001), suggesting that the main effect of HLG significantly increases with age. The association with HLG use, a difference in response time between with and without HLG, was much larger for older (1.5 seconds) than younger (0.3 seconds) participants.

For all 22 participants in this study, a repeated-measures analysis of variance (2 glasses conditions ×2 HLG conditions) also found no significant yellow-lens association (F_1,63 = 0.64; P = .42). However, as reported in Table 3, the performance with the yellow lenses was not better than with the clear lenses in any conditions.

Table 3. Mean Response Time Comparison Between Clear and Yellow Lenses Without and With HLG^a.

Response Time for Detection	Without HLG	With HLG	Difference (95% CI)b	P Value
Navy Blue Shirt Pedestrian by Younger Participants
Clear lens	1.23 (0.06)	1.51 (0.26)	0.31 (−0.25 to 0.25)	.03
Yellow lens	1.29 (0.06)	1.62 (0.24)	0.33 (−0.24 to 0.24)	.01
Difference (95% CI)a	0.06 (−0.07 to 0.07)	0.11 (−0.13 to 0.13)
P value	.10	.09
Orange Shirt Pedestrian by Younger Participants
Clear lens	1.16 (0.05)	1.49 (0.35)	0.33 (−0.24 to 0.24)	.09
Yellow lens	1.27 (0.06)	1.49 (0.17)	0.22 (−0.12 to 0.12)	.04
Difference (95% CI)a	0.11 (−0.03 to 0.03)	0.00 (−0.24 to 0.24)
P value	<.001	.98
Orange Shirt Pedestrian by Older Participants
Clear lens	1.31 (0.07)	2.87 (0.18)	1.56 (−0.13 to 0.13)	<.001
Yellow lens	1.53 (0.14)	2.97 (0.17)	1.44 (−0.05 to 0.05)	<.001
Difference (95% CI)a	0.22 (−0.10 to 0.10)	0.10 (−0.20 to 0.20)
P value	.07	.58

Abbreviation: HLG, headlight glare.

^aPairwise t tests between conditions were not corrected for multiple comparisons, but all responses were worse with the yellow lenses.

^b95% CIs were computed for the difference between 2 groups.

Discussion

Our data suggest that wearing yellow-lens glasses when driving at night does not improve performance in the most critical task: detection of pedestrians. Instead, the data showed that wearing yellow-lens glasses may slightly worsen performance, although that finding was not statistically significant (eAppendix in the Supplement provides power and sample size analysis).

As reported in Table 3, the response times to a pedestrian with an orange shirt (Figure 2B) were slightly shorter under all glasses and HLG conditions compared with those of the pedestrian in the dark navy blue shirt (Figure 2A). With the orange shirt, the association between response time and HLG became nonsignificant (Figure 2B). This finding suggests that changing the pedestrian shirt to the more visible, brighter orange color improved the response time more in the challenging condition (with HLG), while response time in the easier condition (without HLG) may have reached the maximal possible performance for younger individuals (ceiling effect).

Older people experience more difficulties with night driving owing to aging of the eyes and age-related ocular diseases that increase light scatter. Therefore, they are more likely to be the target users for yellow-lens night-driving glasses. Our data (Figure 2C) suggest that the negative effect of oncoming HLG increases substantially for the older individuals, even for those with good VA. Yet, wearing yellow-lens glasses did not improve (ie, more likely worsened) performance either with or without HLG.

Most participants in the study informally expressed that they felt that the yellow-lens glasses increased the brightness of the scene. These subjective impressions are also often expressed in the online user reviews of the yellow-lens night-driving glasses.^26,27,28 This impression may be the reason for the continued interest in yellow-lens night-driving glasses. An impression of improved vision with the yellow-lens glasses, if it does not improve actual performance, may negatively affect safety, as the users may be less cautious when wearing those glasses than they would otherwise be, as speculated by Mace et al.²⁹

Limitations

The study has limitations. Our results and conclusions are based on the relatively small number of participants (n = 22). Considering the consistent negative association between the yellow lens and performance, increasing the sample size may lead to statistical significance, but not the direction, so the small size of this negative outcome is not likely to change with more participants. Although our study was conducted in a driving simulator rather than on a road, the pedestrian encounter events and HLG simulation closely mimicked real-world night-driving condition. We did not explicitly exclude or include individuals with any eye disease or condition. The yellow-lens night-driving glasses are sold to the general population, including people with no specific condition.

Conclusions

Yellow-lens night-driving glasses did not appear to improve pedestrian detection at night or reduce the negative associations between HLG and pedestrian detection performance. This negative association of HLG was greater for older participants. Furthermore, a difference in response time with the yellow lenses was not noted based on pedestrian shirt color. These findings do not appear to support having eye-care professionals advise patients to use yellow-lens night-driving glasses.

Supplement.

eAppendix. Additional Details