Beyond Vision: Light's Effectiveness in Eliciting Human Responses

Price, Luke Llewelyn Anthony (2020). Beyond Vision: Light's Effectiveness in Eliciting Human Responses. PhD thesis The Open University.



Optical radiation affects health via diverse and interconnected mechanisms. The skin and eyes support multiple actinic processes, exploiting environmental optical radiation, including light, to the benefit of the whole body. Sub�optimal exposures can disrupt these processes and in extreme scenarios may cause tissue damage. Natural and artificial lighting can lead to both beneficial and unwanted responses; understanding how to achieve a healthy balance relies on quantitative exposure data and dose�response relationships based on physical measurements.

Through non-visual retinal photoreception, light has a profound effect on daily patterns of human physiology and behaviour. This thesis reviews the spectral weighting function, action spectrum, for the regulation of plasma melatonin, and its relation to photoreceptors, melanopsin, circadian rhythms, standardisation, health advice and eye safety.

In my portfolio, I have contributed to understanding human non�visual responses to light. The human photoreceptor calculation tool I constructed is widely used and supports an International Standard. I published a revised circadian light�drive model based on melanopsin photoreception, and coordinated multidisciplinary advice on shift work health studies.

Short-wavelength light synchronises day and night time activities with the environment. Bright artificial light at night can interfere with this process, and high radiance blue light can cause retinal lesions. I have contributed practical advice on the efficacy of bright light therapy products, confirmed the eye safety of display screens, and raised concerns about the modulation or flicker from some LED lighting.

My published advice is based on field measurements of human exposures to light and experience gained of gathering exposure data. In the final section of my portfolio, my work has included characterising the performance and use of wearable broadband dosimeters and light-weight CCD array spectroradiometers, proposing performance requirements for wearable sensors and developing the closest�matching melanopic light�logger from an existing product

Viewing alternatives

Download history


Public Attention

Altmetrics from Altmetric

Number of Citations

Citations from Dimensions

Item Actions



  • Item ORO ID
  • 70824
  • Item Type
  • PhD Thesis
  • Extra Information
  • Publication 1: Lucas, R. J., Peirson, S. N., Berson, D. M., Brown, T. M., Cooper, H. M., Czeisler, C. A., Figueiro, M. G., Gamlin, P. D., Lockley, S. W., O’Hagan, J. B., Price, L. L. A., Provencio, I., Skene, D. J. & Brainard, G. C. (2014). Measuring and using light in the melanopsin age. Trends in Neurosciences, 37(1), 1â€�9.

    Publication 2: Price, L. L. A. (2014). On the role of exponential smoothing in circadian dosimetry. Photochemistry and Photobiology, 90(5), 1184�1192

    Publication 3: Price, L. L. A., Behrens, T., van Drongelen, A., Garde, A. H., Hogenelst, K., Jensen, M. A., Khazova, M., Nowak, K., Rabstein, S., Udovi�ić, L. & Wolska, A. (2019). Linking the non�visual effects of light with occupational health. International Journal of Epidemiology, 48(5), 1393�1397

    Publication 4: Baczynska, K. & Price, L. L. A. (2013). Efficacy and ocular safety of bright light therapy lamps. Lighting Research & Technology, 45(1), 40�51

    Publication 5: O’Hagan, J. B., Khazova, M. & Price, L. L. A. (2016). Low�energy light bulbs, computers, tablets and the blue light hazard. Eye, 30(2), 230�233

    Publication 6: Price, L. L. A. (2017). Can the Adverse Health Effects of Flicker from LEDs and Other Artificial Lighting Be Prevented?. LEUKOS, 13(4), 191�200

    Publication 7: Price, L. L. A., Khazova, M. & O’Hagan, J. B. (2012). Performance assessment of commercial circadian personal exposure devices. Lighting Research & Technology, 44(1), 17-26

    Publication 8: Price, L. L. A., Hooke, R. J. & Khazova, M. (2014). Effects of ambient
    temperature on the performance of CCD array spectroradiometers and practical implications for field measurements. Journal of Radiological Protection, 34(3), 655�660.

    Publication 9: Baczynska, K. A., Price, L. L. A. & Khazova, M. (2016). Dynamic response of
    CCD array spectroradiometers. Radiation Protection Dosimetry, 171(3), 291�296.

    Publication 10: Price, L. L. A., Lyachev, A. & Khazova, M. (2017). Optical performance characterization of light�logging actigraphy dosimeters. Journal of the Optical Society of America A, 34(4), 545�557.

    Publication 11: Price, L. L. A. & Lyachev, A. (2017). Modification of a personal dosimetry device for logging melanopic irradiance. Lighting Research & Technology, 49(7), 922�927.
  • Keywords
  • occupational health; light exposure; phototherapy; visual perception; circadian rhythms; charge coupled devices; spectrometer; sleep disorders
  • Academic Unit or School
  • Faculty of Science, Technology, Engineering and Mathematics (STEM)
    Faculty of Science, Technology, Engineering and Mathematics (STEM) > Life, Health and Chemical Sciences
  • Associated Research Centre
  • Public Health England
  • Copyright Holders
  • © 2020 The Author
  • Depositing User
  • ORO Import