The Effects of Age, Refractive Status, and Luminance on Pupil Size

Abstract

PurposePupil size is critical for optimal performance of presbyopic contact lenses. Although the effect of luminance is well known, little information is available regarding other contributing factors such as aging and refractive status.MethodsThe cohort population comprised 304 patients (127 male, 177 female) aged 18 to 78 years. Pupils were photographed at three controlled luminance levels 250, 50, and 2.5 cd/m2 using an infra-red macro video camera. Measurements of pupil diameter were conducted after transforming pixel values to linear values in millimeters.ResultsLuminance was the most influential factor with pupil diameter increasing with decreased luminance (p < 0.001, all comparisons). Age was also found to be a significant factor with a smaller diameter in the older groups, but overall the difference was only significant between the pre-presbyopes and the established presbyopes (p = 0.017). Pupil diameter decreased significantly with increasing age, the effect being most marked at low luminance (<0.001). The smallest pupil diameters were measured for hyperopes and the largest for myopes and although refractive error was not a significant factor alone, there was a significant interaction between luminance and refractive error with the greatest differences in pupil diameter between myopes and emmetropes at low luminance (p < 0.001). Pupil diameter changes modeled by multilinear regression (p < 0.001) identified age, luminance, best sphere refraction, and refractive error as significant factors accounting for just over 70% of the average variation in pupil diameter.ConclusionsBoth age and refractive status were found to affect pupil size with larger pupils measured for younger patients and myopes. Designs for multifocal contact lens corrections should take both age and refractive status into consideration; a faster progression from distance to near corrections across the optical zone of the lens is expected to be required for established presbyopes and hyperopes than it is for early presbyopes, myopes, and emmetropes.

Pupil Function in Pseudophakia: Proximal Miosis Behavior and Optical Influence

“…The pupil-age variation in the Winn et al (1994) study for the same age interval is −0.17 mm per decade, which is a value closer to that found in the present pseudophakic population. The relevance of age group in the pupil diameter was recently pointed out by Guillon and colleagues [49], by reporting a smaller pupil sizes in a presbyopic population compared to pre-presbyopic subjects. In practical terms, the performance of optical components within the optical system of the eye, as is the case of the pupil, should be studied using age-matched parameters.…”

“…However cognitive effects have a small effect on pupil size [28]. Other more important factors such as accommodation [45], stimulus contrast [46], luminance [20], retinal eccentricity [47], field size [48] and refractive error [49] were controlled in the experiment, by fixing the light flux at the cornea and using a constant illuminated field, a high contrast central stimulus and a nearly emmetropic population unable to elicite refractive changes by means of accommodation.…”

“…Pupil behavior is mainly driven by the response of the amount of light reaching the corneal plane [28], thus investigating the proximal miosis behavior in the presence of various light levels would have added information on how pupil miosis varies in different lighting conditions. Guillon et al [49] reported significant interactions in pupil size measurements when these were done for different luminance levels, age ranges and refractive error. Essentially, low levels of luminance allow for more interactions between pupil size and factors influencing it due to the wider pupil diameter.…”

Cross‐sectional association between oral health and retinal microcirculation

“…This limitation can be explained by age‐related increase of cataract‐induced lens opacity (Scanlon et al., ). In addition, pupil size decreases with age (Guillon et al., ; Winn, Whitaker, Elliott, & Phillips, ). Both conditions have negative effects on the optical quality of non‐mydriatic funduscopy.…”

A Review of Pupillometry for Human-computer Interaction Studies

“…As already mentioned, age is a major factor in many parameters of the PLR and should be accounted for in all studies [14]. Older participants show decreased amplitude of response [21], increased latency and in some cases decreased velocity [20] as well.…”