Abstract
Purpose :
Given the potential role of wavelengths of lights on eye growth, it is of interest to study the pupillary and accommodative responses with various wavelengths of light. We aimed to determine and compare the pupillary and accommodative responses to blue, white, and red light during reading and an arithmetic (cognitive) task.
Methods :
Thirteen adult participants with myopia (mean age 23.5 ± 2.0 years, SE: 2.45 ± 1.50 D) were recruited and participants signed the informed consent before enrolling into the study. Participants undertook a reading task and computed an arithmetic problem that were presented on a monitor located at 50 cm. Pupil diameter (PD) and accommodative responses (AR) were dynamically recorded during the tasks using an open-field autorefractor (WAM 5500) for 35 s. Tasks were repeated with blue (460 nm), white (2700 K fluorescent light) and red (630 nm) wavelengths. Ocular aberrations were measured with BHVI EyeMapper using natural pupils. Retinal image quality (RIQ) was calculated using VSOTF (Visual Strehl Optical Transfer Function) for various pupil diameters (3-6mm in 1mm steps).
Results :
At baseline (no task, gazing at the grey monitor), AR did not vary (~ 0.75 D±0.29 D) with different wavelengths (p>0.05), whereas PD was smaller with blue (2.71±0.34 mm) vs red (3.32±0.46 mm) and white (3.51±0.54 mm) (p=0.002) lights. With both the reading and cognitive tasks, AR increased by 0.45±0.30 D compared to no task (p=0.03) and remained sustained during the task with no significant variation between the lights. In comparison, PD varied between reading and cognitive tasks and with wavelengths. With the cognitive task, there was an initial PD constriction of 0.08±0.13 mm over 3 s followed by dilation of 0.05±0.16, 0.11±0.28, 0.27±37 mm with blue, white, and red lights. In comparison, for the reading task, PD constricted by 0.07±0.11, 0.11±0.13, 0.24±0.24 mm that was sustained through the task. RIQ decreased with larger pupil diameters (0.51±0.20 vs 0.22±0.14 for 3 mm vs 6 mm) with a mean decrease of 0.1 VSOTF with a 1 mm increase in the PD.
Conclusions :
AR did not vary with the type of near task or the wavelength. Interestingly, PD varied between tasks with the likelihood of a larger PD for cognitive tasks. Irrespective of the task, blue light was more effective than other wavelengths in maintaining a smaller PD and a higher RIQ.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.