Share Email Print
cover

Proceedings Paper

Objective evaluation of the visual acuity in human eyes
Author(s): M. A. Rosales; E. López-Olazagasti; G. Ramírez-Zavaleta; G. Varillas; E. Tepichín
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Traditionally, the quality of the human vision is evaluated by a subjective test in which the examiner asks the patient to read a series of characters of different sizes, located at a certain distance of the patient. Typically, we need to ensure a subtended angle of vision of 5 minutes, which implies an object of 8.8 mm high located at 6 meters (normal or 20/20 visual acuity). These characters constitute what is known as the Snellen chart, universally used to evaluate the spatial resolution of the human eyes. The mentioned process of identification of characters is carried out by means of the eye - brain system, giving an evaluation of the subjective visual performance. In this work we consider the eye as an isolated image-forming system, and show that it is possible to isolate the function of the eye from that of the brain in this process. By knowing the impulse response of the eye´s system we can obtain, in advance, the image of the Snellen chart simultaneously. From this information, we obtain the objective performance of the eye as the optical system under test. This type of results might help to detect anomalous situations of the human vision, like the so called "cerebral myopia".

Paper Details

Date Published: 2 September 2009
PDF: 10 pages
Proc. SPIE 7443, Applications of Digital Image Processing XXXII, 74430N (2 September 2009); doi: 10.1117/12.826594
Show Author Affiliations
M. A. Rosales, Univ. de las Américas Puebla (Mexico)
E. López-Olazagasti, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico)
G. Ramírez-Zavaleta, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico)
G. Varillas, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico)
E. Tepichín, Instituto Nacional de Astrofísica, Óptica y Electrónica (Mexico)


Published in SPIE Proceedings Vol. 7443:
Applications of Digital Image Processing XXXII
Andrew G. Tescher, Editor(s)

© SPIE. Terms of Use
Back to Top