Effects of Light on the Choroid and Pupil
Completed · Not applicable
Conditions studied: Emmetropia, Myopia
In brief
Monochromatic light creates longitudinal chromatic aberration, with short wavelength blue light forming a focal point in front of the retina and long wavelength red light forming a focal point behind the retina. The investigators hypothesize that such chromatic aberrations, induced by exposure to red or blue LED lights, will cause the choroid behind the retina to respond to bring the image into focus by modulating its thickness, either thickening in the case of blue light or thinning in the case of red light. The magnitude and direction of this response is difficult to predict as previous studies have shown opposite findings in non-human primates and rodents. Furthermore, the investigators hypothesize that exposure to red or blue light will induce changes in how the pupil responds to light, because the cells in the eye that are involved in pupil control are most sensitive to blue light.
Key facts
- Study ID
- NCT05852782
- Run by
- University of Houston
- People needed
- 20
- Starts
- 2019-02-01
- Expected to finish
- 2020-02-02
- Last updated by the study team
- 2023-05-10
Who can join
Age: 18 and older. Sex: any. Healthy volunteers: accepted.
You may qualify if…
- ages 18-64
- must be able to comply with the experimental protocol, including collecting saliva and being present for the experiment in the lab on four separate occasions.
- must be willing to abstain from the use of sleep aids 12 hours prior to and for the duration of the study.
- must also be willing to abstain from alcohol and caffeinated beverages (coffee, espresso, energy drinks) or foods enriched with caffeine, such as power bars, the morning of and during each of the four experimental sessions.
You may not qualify if…
- age < 18 or >64 years old
- not willing to collect a saliva sample or be present in the lab on four separate occasions.
- ocular disease that may affect retinal light levels and function (e.g. glaucoma, significant cataract, etc.)
- use of prescription or over-the-counter medications known to affect sleep and cortisol levels.
Where it is running
- University of Houston College of Optometry — Houston, Texas, United States
Full record on ClinicalTrials.gov
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