Abstract
Purpose :
Individuals with congenital Colour Vision Deficiency (CVD) tend to have lower accuracy and longer reaction times in search-based colour tasks. This study investigated the effects of chromatic saturation on visual search performance in individuals with colour vision deficiency.
Methods :
Seven individuals with CVD (3 protans and 4 deutans; all males; average age: 30 ± 2 years) participated in this study. The colour vision defect was identified by HRR plates. Four images (depicting natural sceneries or flowers/fruits or birds/animals or everyday task) for each of the 15 colour combinations (red/green, red/white, red/grey, red/purple, red/orange, red/brown, red/black, green/grey, green/white, green/yellow, green/brown, green/blue, orange/yellow, brown/orange and black/brown) were manipulated into two categories namely ‘low’ (-75 %) and ‘high’ saturation (+75 %) using the GIMP software (Version 2). The altered image sets (low and high) along with ‘original’ set (unaltered) were presented on a colour-calibrated monitor using the Psychopy program (Version 2.7). The CIE 1931 (x, y) co-ordinates for each colour were obtained based on the tristimulus measured using an XRite Colorimeter. The participants viewed the screen binocularly from a test distance of 1m. The instructions for identifying the specific-coloured target in each presentation preceded the image by three seconds. The participants had to respond within 3 seconds following the image presentation by clicking on the target in the image. The display monitor was screen-recorded throughout the test which was later manually analyzed to derive the correctness of the response. The visual performance was computed as a product of accuracy percentage and reciprocal of the reaction time (s).
Results :
Overall the improvement in visual performance (≥ 10 % than original) in ‘high’ saturation conditions was observed for green/blue, brown/black and red/green combinations. On the other hand, increasing saturation for combinations such as orange/brown and green/yellow deteriorated the visual performance (≥ 10 % poorer than original) in both the groups.
Conclusions :
The improvement/worsening of visual search performance on increasing the saturation of the images depends on specific colour combinations. Therefore, specific recommendations for increase in colour saturation for improvement in visual performance can potentially be developed.
This is a 2021 ARVO Annual Meeting abstract.