I. Insect sight and the defining power of composite eyes

Mallock, A.

doi:10.1098/rspl.1894.0016

Cited by 25 publications

(4 citation statements)

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“…(8», we find in the diffraction limited compound eye that the resolution increases only with the square root of the size of the eye (Mallock, 1894;Barlow, 1952;de Vries, 1956;Kuiper and Leutscher-Hazelhoff, 1965) or, if eye size and body height are proportional, to the square root of body height H.…”

Section: Compound Eyesmentioning

confidence: 96%

The Resolution of Lens and Compound Eyes

Kirschfeld¹

1976

Proceedings in Life Sciences

144

112

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Two distinctly different types of eyes have been highly developed in evolution: lens eyes (= camera eyes) in vertebrates, some molluscs and arachnids and compound eyes in arthropods. Based on his comparative studies of the optical properties of compound and lens eyes, Exner (1891) concluded that both types of eyes are optimally adapted for different functions: lens eyes with their high angular resolution seem to more useful for pattern recognition, whereas the compound eyes, with their poor resolution, are thought to be specialized for movement perception. This view is still generally accepted (see the textbooks of Scheer, 1969, Kaestner, 1972). Furthermore, the small facet diameters of the ommatidia in compound eyes seem to cause a poor absolute sensitivity (Exner, 1891; Barlow, 1952; Kirschfeld, 1966; Prosser and Brown, 1969; Snyder et al., 1973). Some insects are said, however, to have higher temporal resolution than humans (Autrum, 1948)

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Section: Compound Eyesmentioning

confidence: 96%

The Resolution of Lens and Compound Eyes

Kirschfeld¹

1976

Proceedings in Life Sciences

144

112

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“…Over a century ago, vision scientists imagined that such eyes "…[give] a picture about as good as if executed in rather coarse wool-work and viewed at a distance of a foot" (Mallock, 1894). The spatial resolution of the fly visual system is three orders of magnitude worse than that of humans (Land and Nilsson, 2002) and thus presents a problem for the flying animal: fruit flies cannot visually discriminate food sources at any appreciable distance.…”

Section: Introductionmentioning

confidence: 99%

Context-dependent olfactory enhancement of optomotor flight control inDrosophila

Chow

Frye

2008

Journal of Experimental Biology

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“…This notion, going back to Mallock (1894), neglects the important contribution to visual acuity by the visual waveguides, the rhabdomeres of flies and the fused rhabdoms of bees and butterflies. Fig.·4 shows that diffraction is dominant when the rhabdomere is so slender that only one mode is allowed or, in a wider rhabdomere, when the pupil has extinguished all higher order modes.…”

Section: Discussionmentioning

confidence: 99%

Visual acuity of fly photoreceptors in natural conditions - dependence on UV sensitizing pigment and light-controlling pupil

Stavenga

2004

Journal of Experimental Biology

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SUMMARY The effect of the UV-absorbing sensitizing pigment of fly photoreceptors on absolute, spectral and angular sensitivity was investigated with a wave-optics model for the facet lens-rhabdomere system. When sky light was used as a UV-rich light source, one sensitizing pigment molecule per rhodopsin increased the photoreceptor absorption by 14-18% with respect to pure rhodopsin, whilst two sensitizing pigment molecules per rhodopsin increased the absorption by 20-27%. Upon light adaptation, when the pupil mechanism is activated,photoreceptor absorption decreases; in the housefly, Musca, by up to 6-fold. The fully light-adapted pupil diminishes the photoreceptor's acceptance angle by a factor of ∼0.6 due to selective absorption of higher order waveguide modes. Spatial acuity of dark-adapted photoreceptors is more or less constant throughout the visual wavelength range, including the UV,because the waveguide optics of the rhabdomere compromise acuity least at wavelengths most limited by diffraction of the facet lens. Diffraction is not the general limiting factor causative for UV sensitivity of insect eyes. Visual acuity is governed by diffraction only with a fully light-adapted pupil, which absorbs higher waveguide modes. Closure of the blue-absorbing pupil causes a UV-peaking spectral sensitivity of fly photoreceptors. The sensitizing pigment does not play an appreciable role in modifying spatial acuity, neither in the dark- nor the light-adapted state, due to the dominant contribution of green light in natural light sources.

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I. Insect sight and the defining power of composite eyes

Cited by 25 publications

References 0 publications

The Resolution of Lens and Compound Eyes

The Resolution of Lens and Compound Eyes

Context-dependent olfactory enhancement of optomotor flight control inDrosophila

Visual acuity of fly photoreceptors in natural conditions - dependence on UV sensitizing pigment and light-controlling pupil

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