Factors affecting crowded acuity: eccentricity and contrast.

ABSTRACT:

Purpose

Acuity measurement is a fundamental method to assess visual performance in the clinic. Little is known about how acuity measured in the presence of neighboring letters, as in the case of letter charts, changes with contrast and with nonfoveal viewing. This information is crucial for acuity measurement using low-contrast charts and when patients cannot use their fovea. In this study, we evaluated how optotype acuity, with and without flankers, is affected by contrast and eccentricity.

Methods

Five young adults with normal vision identified the orientation of a Tumbling-E presented alone or in the presence of four flanking Tumbling-Es. Edge-to-edge letter spacing ranged from 1 to 20 bar widths. Stimuli were presented on a white background for 150 ms with Weber contrast

SUBMITTER: Coates DR 

PROVIDER: S-EPMC3837536 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature