CORNEAL CURVATURES AND REFRACTIONS OF CENTRAL-AMERICAN FROGS

We employed neutralizing infrared videophotorefraction and photokerato metry to examine the manifest refractions and corneal curvatures of 21 species of anurans (frogs and toads) in five families (Dendrobatidae, Bufonidae, Centrolenidae, Leptodactylidae, and Hylidae) resident in C entral America. We found that all of the anurans exhibited hyperopic r efractions in air, but that the observed hyperopia was not totally exp lained by the small eye artefact (Glickstein & Millodot, 1970). An all ometric comparison of the corneal radii of these small anurans with th ose of a large number of other vertebrates, inferred from ocular axial lengths, showed that their corneal radii increased significantly more rapidly with increasing body size than that of other vertebrates gene rally (allometric slope constants: anurans: 0.270 +/- 0.032; other ver tebrates: 0.151 +/- 0.004). Among the anurans examined, nocturnal Hyli ds had significantly larger eyes than diurnal Dendrobatid frogs and Bu fonid toads. Copyright (C) 1996 Elsevier Science Ltd.