Summary
This thesis investigates chromatic afterimages and pupillary responses using psychophysical and objective techniques, with implications for understanding how different photoreceptor classes contribute to visual processing. Key findings challenge assumptions about melanopsin's role in dynamic pupil responses and reveal compensatory neural reorganization in congenital visual field loss, which may inform clinical lighting assessments.
Key Findings
- Melanopsin does not appear to contribute to dynamic pupil light reflex responses in humans, based on evidence from rod monochromat and retinitis pigmentosa subjects.
- Patients with acquired cortical damage (homonymous hemianopia) show absent or reduced pupil responses in the blind hemifield, whereas congenitally affected patients show similar or enhanced responses compared to their sighted hemifield, suggesting neural pathway reorganization.
- In LHON subjects, not all ganglion cell classes are affected uniformly; rod-mediated pupil light reflex responses were least affected.
- A model was developed predicting colour confusion lines and pupil colour response characteristics in dichromats at any given background chromaticity.
Categories
Eye Health & Vision: Investigates pupillary light reflex responses across various visual conditions including hemianopia, retinitis pigmentosa, and optic neuropathy.
The Science of Light: Examines melanopsin's role in dynamic pupil light reflex responses and develops models for luminance and colour processing using photoreceptor-isolating stimuli.
Author(s)
W Bi
Publication Year
2012
Related Publications
Eye Health & Vision
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Genetic reactivation of cone photoreceptors restores visual responses in retinitis pigmentosa
- Melanopsin and rod–cone photoreceptors play different roles in mediating pupillary light responses during exposure to continuous light in humans
- Characteristic patterns of dendritic remodeling in early-stage glaucoma: evidence from genetically identified retinal ganglion cell types
- Intrinsically photosensitive melanopsin retinal ganglion cell contributions to the pupillary light reflex and circadian rhythm
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice