Participants were excluded from the pupil response study if they had pupillary malformations, severe cataract (N = 5), self-reported history of glaucoma in either eye, penetrating eye wounds to both eyes, and eye surgery to both eyes that involved the muscle; if they used cholinesterase inhibitors or prescribed ocular medications (N = 36); or if they were unable to complete the task without excessive blinking (N = 10). Here, BCHE is linked to glaucoma.