PubMed HealthSearch

PubMed · 6824054

A multipurpose low-vision aid.

Abstract

We constructed a low-vision aid for a 61-year-old patient who had familial macular degeneration and a visual acuity of 20/300. The aid consisted of a spectacle lens incorporating his distance prescription as the carrier, a high-plus bifocal reading addition, and the high-minus ocular lens of a Galilean telescope of variable magnification. The objective lens of the telescope can be carried as a folding, dual-lens, hand magnifier.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A Safir, D Loupe, E S Naccari, A J Fitzgerald. 1983. A multipurpose low-vision aid.. https://doi.org/10.1016/0002-9394(83)90020-x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

[Progress in eyeglass optics].

In this article product developments for ophthalmic lenses are discussed: new materials, designs and coatings. High-index plastic substrates allow to offer corrections which are simultaneously light and thin and for the first time there are high performant plastic photochromic lenses. Head and eye movements with latest generation's progressives are very similar to natural vision behaviour. Special aspheric designs have been developed for comfortable vision for near and intermediate distances. Finally there are new coatings which protect the high quality surfaces of plastic lenses distinctly longer than before.

Eyeglasses

Oblique central refraction in spherocylindrical corrections with both faceform and pantoscopic tilt.

Thin lens equations, accurate to third order, are presented for the effective spherocylindrical parameters for oblique central refraction (OCR) through spherocylindrical lenses with both faceform and pantoscopic tilt. The equations can also be used to find the parameters of a lens that compensates for the tilts. Accuracy of the equations was checked by exact ray trace results.

Eyeglasses

Spherocylindrical refractive errors and visual acuity.

BACKGROUND: Understanding the relation between refractive error and visual acuity is complicated if astigmatic blur is present. No models are in widespread use that allow the combination of spherical and astigmatic errors for the purpose of predicting visual performance. METHODS: Models for combining spherical and astigmatic errors are discussed, and predictions of these models using data from the literature are presented. RESULTS: Three models for combining astigmatic with spherical errors are shown to predict visual acuity performance in uncorrected myopic refractive errors. A dioptric vector addition model is shown to have advantages over other candidate models. CONCLUSIONS: It is possible to combine spherocylindrical refractive errors into a single value when the objective is to correlate these values with visual acuity performance.

Eyeglasses