Vanishing Optotypes
- 1 August 1986
- journal article
- research article
- Published by American Medical Association (AMA) in Archives of Ophthalmology (1950)
- Vol. 104 (8) , 1194-1198
- https://doi.org/10.1001/archopht.1986.01050200100060
Abstract
• Acuity test letters generated on a television monitor were studied with regard to detection and resolution thresholds, both for the native configurations and after high-pass spatial frequency filtering. Comparisons were made with printed acuity charts of different contrast. Filtering diminished the interval between detection and resolution thresholds. Under some circumstances, a small (1 dB, about 26%) increment in size could make a previously invisible optotype clearly visible, or vice versa. The termvanishing optotypeis suggested for acuity targets with this peculiar property. Vanishing optotypes do not seem useful for routine clinical acuity testing, but they may be advantageous, for example, in preferential looking-acuity tests for infants and visual field examinations. Like the present tests, such novel applications can be generated relatively easily on personal computers.This publication has 9 references indexed in Scilit:
- Psychophysics of reading—I. Normal visionVision Research, 1985
- Low-contrast letter charts in early diabetic retinopathy, ocular hypertension, glaucoma, and Parkinson's disease.British Journal of Ophthalmology, 1984
- Low-Contrast Letter Charts as a Test of Visual FunctionOphthalmology, 1983
- Estimating LD50Using the Probit Technique: A Basic Computer ProgramDrug and Chemical Toxicology, 1983
- How good is normal visual acuity?Albrecht von Graefes Archiv für Ophthalmologie, 1981
- High-pass spatial frequency letters as clinical optotypesVision Research, 1978
- Vision of Young ChildrenArchives of Ophthalmology (1950), 1969