Sharp vision: a prerequisite for compensation to myopic defocus in the chick?

Current Eye Research
S T NevinChristine F Wildsoet

Abstract

Compensatory responses to focusing errors imposed by spectacle lenses in chicks, tree shrews and primates leave little doubt that active emmetropization can occur, and debate is now centered on whether this process is uni-directional or bi-directional in nature. To provide further insight into this emmetropization process, the studies reported in this paper addressed the question of whether access to sharp vision is necessary for compensation to myopic defocus in the chick. Two different experimental paradigms were used to address the above question: (A) Myopic defocus was imposed, either with +15 or +40 d lenses alone or with +15 D lenses on eyes made myopic by 7 days of form deprivation; these treatments result in a shift in the plane of focus of the eye (far point) to 6.67, 2.5 cm and approximately 3.5 cm resp., with only objects at or closer than these planes being in focus. The addition to the lenses of stand-off cones, either 2.5 or 5 cm in length, further limited access to (or precluded) sharp vision by controlling how closely the chicks could approach objects. One group that had sharp vision precluded also underwent optic nerve section. (B) A range of positive lenses (+15 to +65 D) were used on their own to impose myopi...Continue Reading

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Citations

Aug 23, 2008·Investigative Ophthalmology & Visual Science·Likun AiChristine F Wildsoet
Oct 16, 2003·Clinical & Experimental Optometry : Journal of the Australian Optometrical Association·Katrina L SchmidKate M Wallace
Jan 31, 2012·Clinical & Experimental Optometry : Journal of the Australian Optometrical Association·Trine Langaas, Patricia M Riddell
May 15, 2013·Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists)·Frances J Rucker
May 15, 2013·Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists)·David S HammondChristine F Wildsoet
Feb 26, 2013·Experimental Eye Research·Marita Feldkaemper, Frank Schaeffel
Aug 18, 2004·Neuron·Josh Wallman, Jonathan Winawer
Jul 18, 2012·Vision Research·David S Hammond, Christine F Wildsoet
Oct 4, 2005·Vision Research·Katrina L SchmidRobert Hess
Jan 5, 2008·Optometry and Vision Science : Official Publication of the American Academy of Optometry·Trine LangaasJan Richard Bruenech
Jan 28, 2021·Investigative Ophthalmology & Visual Science·Erica G LandisMachelle T Pardue
Apr 29, 2021·Investigative Ophthalmology & Visual Science·Jost B JonasJames S Wolffsohn
Oct 2, 2001·Controlled Clinical Trials·L HymanUNKNOWN COMET Group
Jul 7, 2021·Experimental Eye Research·Jody A SummersAndrei V Tkatchenko
Nov 18, 2021·Documenta Ophthalmologica. Advances in Ophthalmology·Satish Kumar GuptaPavan Kumar Verkicharla

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