Topic
Light sensitivity
About: Light sensitivity is a research topic. Over the lifetime, 417 publications have been published within this topic receiving 5504 citations.
Papers published on a yearly basis
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Papers
TL;DR: It is suggested that the circadian system's sensitivity to light can be affected by a recent change in light history, as assessed by the magnitude of the suppression of melatonin secretion by nocturnal light.
Abstract: We investigated the impact of light exposure history on light sensitivity in humans, as assessed by the magnitude of the suppression of melatonin secretion by nocturnal light. The hypothesis was that following a week of increased daytime bright-light exposure, subjects would become less sensitive to light, and that after a week of restriction to dimmer light they would become more sensitive. During the bright week, subjects (n = 12) obtained 4.3 +/- 0.4 hr of bright light per day (by going outside and using light boxes indoors). During the dim week, they wore dark goggles (about 2% light transmission) when outside during daylight and spent 1.4 +/- 0.9 hr per day outside. Saliva samples were obtained every 30 min for 7 hr in dim light (<15 lux) on two consecutive nights (baseline and test night) at the end of each week. On the test night, 500 lux was presented for 3 hr in the middle of the collection period to suppress melatonin. There was significantly more suppression after the dim week compared with after the bright week (to 53 versus 41% of the baseline night values, P < 0.05). However, there were large individual differences, and the difference between the bright and dim weeks was most pronounced in seven of the 12 subjects. Possible reasons for these individual differences are discussed, including the possibility that 1 wk was not long enough to change light sensitivity in some subjects. In conclusion, this study suggests that the circadian system's sensitivity to light can be affected by a recent change in light history.
420 citations
TL;DR: In this paper, the spectral sensitivity of non-image-forming responses in two profoundly blind subjects lacking functional rods and cones (one male, 56 yr old; one female, 87 yr old) was examined and found that short-wavelength light preferentially suppressed melatonin, reset the circadian pacemaker, and directly enhanced alertness compared to 555 nm exposure.
375 citations
TL;DR: It is found that, on average, humans are highly sensitive to evening light, and individual-level dose–response curves to light-induced melatonin suppression using a within-subjects protocol demonstrate that the same evening-light environment is registered by the circadian system very differently between individuals.
Abstract: Before the invention of electric lighting, humans were primarily exposed to intense (>300 lux) or dim (<30 lux) environmental light�stimuli at extreme ends of the circadian system�s dose�response curve to light. Today, humans spend hours per day exposed to intermediate light intensities (30�300 lux), particularly in the evening. Interindividual differences in sensitivity to evening light in this intensity range could therefore represent a source of vulnerability to circadian disruption by modern lighting. We characterized individual-level dose�response curves to light-induced melatonin suppression using a within-subjects protocol. Fifty-five participants (aged 18�30) were exposed to a dim control (<1 lux) and a range of experimental light levels (10�2,000 lux for 5 h) in the evening. Melatonin suppression was determined for each light level, and the effective dose for 50% suppression (ED50) was computed at individual and group levels. The group-level fitted ED50 was 24.60 lux, indicating that the circadian system is highly sensitive to evening light at typical indoor levels. Light intensities of 10, 30, and 50 lux resulted in later apparent melatonin onsets by 22, 77, and 109 min, respectively. Individual-level ED50 values ranged by over an order of magnitude (6 lux in the most sensitive individual, 350 lux in the least sensitive individual), with a 26% coefficient of variation. These findings demonstrate that the same evening-light environment is registered by the circadian system very differently between individuals. This interindividual variability may be an important factor for determining the circadian clock�s role in human health and disease. © 2019 National Academy of Sciences. All rights reserved.
350 citations
TL;DR: A daily rhythm of sensitivity to these standard light periods was found in flying squirrels otherwise maintained in constant darkness.
Abstract: Single 10-minute light periods can cause a phase shift in the rhythm of the daily locomotor activity of flying squirrels otherwise maintained in constant darkness. A daily rhythm of sensitivity to these standard light periods was found.
170 citations
Patent•
6 Feb 2012TL;DR: In this article, a camera unit generates a processed digital image by augmenting color image data with infrared image data according to the level of ambient light exposure, and the image data is processed into a digital image, according to a selected mode of operation for the camera unit, using colour image data only when the ambient light is high, but augmenting the color images with infrared images when the level is low to increase the color luminance of the final image.
Abstract: A camera unit generates a processed digital image by augmenting color image data with infrared image data according to the level of ambient light exposure. The camera has an ambient light sensor that detects the level of ambient light in the camera unit and an image sensor that provides image data. One or more quantum dot layers may be included in the image sensor. A camera controller adapts the camera unit for operation in different modes that are selectable based on the levels of detected ambient light. The image data is processed into a digital image, according to the selected mode of operation for the camera unit, using color image data only when the level of ambient light is high, but augmenting the color image data with infrared image data when the level of ambient light is low to increase the color luminance of the final processed digital image.
121 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 1 |
| 2023 | 1 |
| 2022 | 6 |
| 2021 | 10 |
| 2020 | 19 |
| 2019 | 12 |