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Updated: Jun 29, 2026

Determination of Photoreceptor Cell Spectral Sensitivity in an Insect Model from In Vivo Intracellular Recordings
Published on: February 26, 2016
The optical sensitivity of compound eyes: theory and experiment compared
Rikard Frederiksen1, Eric J Warrant
1Department of Cell and Organism Biology, Lund University, Helgonavägen 3, 22362 Lund, Sweden. rikard.frederiksen@cob.lu.se
Abstract:
The Land sensitivity equation is a well-known tool for comparing optical performance between eyes. Despite this, the equation has never been experimentally tested. Here, we present, to our knowledge, the first experimental validation of the equation. We have investigated different insect species active at different intensities, and possessing different types of compound eyes, to compare ratios of calculated sensitivities to ratios determined experimentally. Experimental optical sensitivities were measured by adjusting the intensity of an external light source until photoreceptors in the different eyes produced roughly equal numbers of photon responses ('bumps') per second. The sensitivity ratios obtained in this manner agree well with those obtained using the equation. We conclude that the Land equation remains an excellent tool for comparing sensitivities between different eyes.
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