Abstract
Recent experiments suggest that an afocal lens system may occur in insect apposition eyes which are traditionally believed to contain focal systems. We present a theoretical analysis of lens-photoreceptor systems with focal and afocal optics. A simple parameterization of the systems is obtained and formulas are given for calculating receptor response to on-axis incident light and angular sensitivity. The simple parameterization and formulas allow the different lens photoreceptor systems to be compared: both systems may be similarily optimized for a given wavelength, but the focal lens may be marginally superior over a range of wavelengths. Possible refinements to the theory are discussed.
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Pask, C., Garth, S.J. Comparison of focal and afocal optics in insect eyes. Biol. Cybern. 58, 337–344 (1988). https://doi.org/10.1007/BF00363943
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DOI: https://doi.org/10.1007/BF00363943