Light Colour and the Body Clocks


This project aims to advance our understanding of the effects of light on the body clocks and develop a detailed biophysical model of circadian photoreceptor system that is responsible for the non-visual effects of light on human physiology.


Dr Svetlana Postnova

Research Location

School of Physics

Program Type



Light is the key time cue for our circadian clocks. These clocks are located in every cell and every organ controlling the timing of all biological processes in a body, including sleep-wake, alertness, metabolism, immune function, and hormonal rhythms. Light enters the brain via the retina and acts to synchronize the brain clock, which in turn affects all other clocks. However, not every wavelength has the same effect. Different light colors have different impact on the clock’s phase, which is mediated by the interplay of the photoreceptors in the eye. The key player in circadian effects of light is melanopsin that is most sensitive to blue light (peak at 480 nm), but the rods and cones are involved as well. The exact structure of the photoreceptor system responsible for the circadian effects of light is yet to be fully understood. 

This project will use biophysical modelling to bring together different experimental finding in a unified theory explaining the complex biological system of interacting photoreceptors in the eye and its action on the body clocks.

Additional Information

Candidates will require quantitative background, e.g., physics, mathematics, engineering, computer science and interest in biological systems. 

HDR Inherent Requirements  

In addition to the academic requirements set out in the Science Postgraduate Handbook, you may be required to satisfy a number of inherent requirements to complete this degree. Example of inherent requirement may include:   

  • Confidential disclosure and registration of a disability that may hinder your performance in your degree;
  • Confidential disclosure of a pre-existing or current medical condition that may hinder your performance in your degree (e.g. heart disease, pace-maker, significant immune suppression, diabetes, vertigo, etc.);
  • Ability to perform independently and/or with minimal supervision; 
  • Ability to undertake certain physical tasks (e.g. heavy lifting);  
  • Ability to undertake observatory, sensory and communication tasks;  
  • Ability to spend time at remote sites (e.g. One Tree Island, Narrabri and Camden);  
  • Ability to work in confined spaces or at heights;  
  • Ability to operate heavy machinery (e.g. farming equipment);  
  • Hold or acquire an Australian driver’s licence;  
  • Hold a current scuba diving license;  
  • Hold a current Working with Children Check;  
  • Meet initial and ongoing immunisation requirements (e.g. Q-Fever, Vaccinia virus, Hepatitis, etc.)   

You must consult with your nominated supervisor regarding any identified inherent requirements before completing your application.

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Biophysical modelling, computational biology, Eye, photoreceptors, brain dynamics, dynamical systems, complex systems, body clocks, LIGHT, spectrum, wavelength

Opportunity ID

The opportunity ID for this research opportunity is: 2730

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