The emmetropization mechanism uses multiple visual cues, such as optical defocus and wavelengths of light, to control eye growth and refractive state. However, the mechanisms by which these visual cues produce growth signals and assist the emmetropization mechanism in controlling eye growth remains unclear. We use tree shrews as an animal model to study how the emmetropization mechanism 1) integrates visual information to generate growth signals, 2) processes these signals to modulate eye
growth, and 3) fails or loses efficiency in some individuals leading to the development of myopia (nearsightedness).

  1. Khanal S, Norton TT, Gawne TJ. Limited bandwidth short-wavelength light produces slowly-developing myopia in tree shrews similar to human juvenile-onset myopia. Vision Res. 2022 Dec 16;204:108161.
  2. Khanal S*, Norton TT, Gawne TJ. Amber light treatment produces hyperopia in tree shrews. Ophthalmic Physiol Opt. 2021 Sep;41(5):1076-1086. PMID: 34382245; PMCID: PMC8929402.
  3. Norton TT, Khanal S, Gawne TJ. Tree shrews do not maintain emmetropia in initially-focused narrow-band cyan light. Exp Eye Res. 2021 May;206:108525.