Effects of Viewing Angle and Contrast Ratio on Visual Performance using TFT-LCD

This study intends to investigate the effects of viewing angle for horizontal and vertical axis, and contrast ratio on visual performance during TFT-LCD visual work. Two dependent measures are collected: visual acuity and search performance. The measure of minimal separable visual angel of Landolt-C is used to evaluate the visual acuity. Search performance measured by correct percentage of searching task on pseudo-text. Results showed that viewing angle for horizontal and vertical axis, and contrast ratio significantly affect visual performance. Subjects at 0° and 15° on horizontal and vertical axis had better visual performance than at 30° and 45°. Visual performance increased as contrast ratio increased up to 11:1 and then slightly decreased once the contrast ratio was greater than 11:1.