A note about retinal structure and visual acuity. A light microscopic study of the cones in fovea centralis

Abstract

Purpose: Production of reliable sections of fovea centralis of primate retina. Methods: Rhesus monkey eyes were processed using a new technique known to minimize artefacts and cell-shrinkage in other tissues. An in vivo vascular perfusion-fixation technique with an isotonic fixative followed by a process of slow infiltration with small increments in concentrations mere used. Results: Tangential 1 μm thick serial-sections showed a very good morphology. An average cone-to-cone-center distance of 3.8 μm in the central part of the fovea centralis was found. A cone-to-cone-center distance of 2.2-2.6 μm is suggested in the literature. Conclusion: In spite of the limited study we believe that the new technique has resulted in less tissue shrinkage. Our results are discussed in relation to maximal possible resolution of the eye. Our calculations (for green light) support the idea that the structure of the fovea centralis and the refractive media of the eye are developed close to perfection.