Age related changes of longitudinal chromatic aberration on Color Visual Acuity

Abstract

 

Purpose

 

To study the age related changes of longitudinal chromatic aberration (LCA) on color visual acuity (CVA).

 

Methods

 

Eight normal eyes of 8 subjects were enrolled in this study. All the subjects had no ocular disease or color anomaly. The mean age was 34.3±6.3 years old (27~47). The mean spherical equivalent was -2.28±2.33D. They had best corrected visual acuity of 20/13 or above. We utilized a laptop personal computer and a Liquid Crystal Display (ColorEdge CG245W, EIZO Corp., Ishikawa, JPN) to display the Ladnolt rings. The Landolt rings were colored with four colors (R: Red, GY: Green-Yellow, BG: Blue-Green, BP: Blue-Purple) in the 15 colors (Chroma 6) of NEW COLOR TEST (Lanthony). The dominant-wavelength values were R: 607 [nm], GY: 566 [nm], BG: 488[nm], BP: 440[nm]. The background was colored with white point D65 (achromatic color). The luminance of the background and the Landolt ring color was equiluminance (30 [cd/m²]) based on colorimetry. The CVAs of four colors were measured by 0.5D increments using addition lenses from +1.0 to -2.0D with the best correction. The visual distance was 3 [m]. This experiment was conducted in a dark room. The LCA was the delta between the R (long-wavelength) and BP (short-wavelength) with the use of the addition lens with which was obtained best visual acuity.

 

Results

 

Figure 1 shows the results of CVA for each addition lens. The addition lens which obtained the best CVA were R: 0D (best correction), GY, BG, BP: -0.5D. Figure 2 shows the results of age-related changes of LCA. The LCA and age showed the significant positive correlation (r=0.766, p=0.0310).

 

Conclusions

 

Our study shows that LCA can be evaluated by CVA numerically and subjectively. We expect that LCA evaluated by CVA can be useful data to attain best corrected visual acuity in infant, because the LCA was high in young subjects.  

 

Figure 1. CVA for each addition lens (+1.0 ~-2.0) in four colors (R: Red, GY: Green-Yellow, BG: Blue-Green, GY: Green-Yellow, BP: Blue-Purple).

 

 

Figure 2. Age-related changes of chromatic aberration. The chromatic aberration means the delta of the addition lens which obtains best visual acuity by the most positive side of the lens between the visual acuity of Red and Blue-Purple.