Matthiessen's ratio

In optics, Matthiessen's ratio is the ratio between the distance from the centre of the lens to the objective, versus the lens radius^[1].

This is of particular importance in fish, where the value may decrease from as high as 3.6 to 2.3^[1], decreasing the focal ratio of the lens. A higher focal ratio is thought to compensate for the relatively high Matthiessen’s ratio brought about by constraints of small eye size during early development. This provides a means for larval fish to focus images from different distances, before the ability to accommodate is gained^[1].

References

^ ^a ^b ^c Shand, J. (1999). "Optics of the developing fish eye: comparisons of Matthiessen's ratio and the focal length of the lens in the black bream Acanthopagrus butcheri (Sparidae, Teleostei)". Vision research. 39 (6): 1071–1078. ISSN 0042-6989. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

[shand-1] Shand, J. (1999). "Optics of the developing fish eye: comparisons of Matthiessen's ratio and the focal length of the lens in the black bream Acanthopagrus butcheri (Sparidae, Teleostei)". Vision research. 39 (6): 1071–1078. ISSN 0042-6989. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

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