Pupillometry measures the size and reactivity of the pupil, the dark circle at the eye’s centre through which light enters. Typically, the pupil contracts and dilates depending on the amount of ...

Changes in pupil size or movement might signal mental health issues such as anxiety, neurological disorders, or drug use.

For years, scientists have studied pupil size to understand attention, emotion, and medical conditions. Three key factors were known to influence how pupils react: light exposure, cognitive effort ...

while low light makes your pupils grow larger. Pupil size is controlled by the brain, which receives signals from each retina and sends a message for your eyes to adjust to the light. Muscles in ...

As we age, our eyes change: the lens becomes thicker and yellow, and our pupil size and number of photoreceptors reduce. Less light, then, reaches the biological clock in our brain, making it more ...