Sankhajyoti Saha, M.Optom

Assistant Professor, NSHM Knowledge Campus, Kolkata, India

Editorial Assistant, Vision Science Academy


Vision Science Academy Exclusive

What do a Scuba diver, Mahendra Singh Dhoni while hitting the world cup winning six and a photo of a dead person have in common? The answer is a knotty one; each of them shares a restrained dilation of pupils in their eyes.

Apart from changing size in light, our eye’s pupil shares some psychological commotion as well.

Pupils – outside the clinic

The dilation pathway is a subcortical pathway that starts at the hypothalamus and the Locus Coeruleus (LC). The adaptive-gain theory, proposed by Aston-Jones & Cohen (2005), is based on the psycho-sensory pupil response that deals primarily with the Locus Coeruleus (LC) to regulate the modes of behaviour. (1)

The magnitude of one Scholastic Aptitude Test (Cognitive tasks) suggested greater “Task-Evoked Pupillary dilation” is more in lower-scoring subjects as compared to intelligent ones. Because for lower-scoring individuals, a greater amount of cognitive concentration is required. It indicates that pupil dilation emerges during some cognitively challenging tasks (Psychometric intelligence). (2)

Figure 1: Pupil- the reflection of our tasks

“Pupil size increases in proportion to the difficulty of a task at hand” Princeton University psychologist Daniel Kahneman says in his book. Stimulation of the autonomic nervous system’s sympathetic branch, known for triggering “fight or flight” responses when the body is under stress, induces pupil dilation. (3)


“Fight or Flight” is a defence mechanism that is controlled by the Adrenaline hormone. As soon as the body faces some threatening or stressful or tricky situation which is processed by the amygdala, the hypothalamus in the brain signals to the adrenal medulla to produce adrenaline. The adrenal glands produce adrenaline by transforming the amino acid tyrosine into dopamine, which is known as “feel-good-hormone”. (4-5)

Chronic effect of Adrenaline Spikes:

Though Adrenaline Rush (AR) can be considered a pleasing effect, AR for an extended period is not well documented in the literature. Chronic stimulation of the sympathetic nervous system can raise the risk of anxiety, nervousness, dizziness, palpitation, dyspnoea, tremors, and nausea. (6) Experiencing AR for a prolonged time leads to “stress-related macular degeneration”, as a result of increased cortisol rates, which disrupt blood flow from the eye to the brain. (7)

Take Home messages:

Psychology says to nurture things that give us an immense feeling of existence. To “make your move” by watching your date’s pupil is still considered as a magical gesture.

People are preoccupied with Cognitive Distortion (Negative Bias), which highlights a tendency to invest more attention to nasty things. Endorse AR as your good buddy. AR will be triggered when we endeavour for something new. Make an effort to enroll in some new skills, try to explain one topic to a stranger, take an ice shower, run uphill, and take a scuba dive, which eventually accelerates our AR. This self-administration paradigm will be reframed and balanced with learning new realistic patterns and then provocateur the negative perceptions.

A growing body of literature has suggested using task-evoked pupil dilations as a potential psychophysiological index of cognitive effort. This “Goal-directed-behaviour” should be influential as well as an equilibrium between an individual’s cognitive capacity and intention to invest cognitive efforts at that particular moment. To evolve such regulation, the focus should be to quantify the momentary amount of cognitive effort exerted by an individual in favour of their tasks. (8)

People should be notified about the prospect and essence of AR, before they acquire it, in order to avoid a wrong sense of aversion.



  1. Mathôt S. (2018). Pupillometry: Psychology, Physiology, and Function. Journal of cognition1(1), 16.
  2. Ahern, S., & Beatty, J. (1979). Pupillary responses during information processing vary with Scholastic Aptitude Test scores. Science (New York, N.Y.)205(4412), 1289–1292.
  3. Fong, J. (2012, December 7). Eye-opener: Why do pupils dilate in response to emotional states? Scientific American. Retrieved December 8, 2022, from
  4. Harmony Place. (2017, September 14). What happens during an adrenaline rush? Harmony Place. Retrieved December 8, 2022, from
  5. Ghanshyambhai, D. M. T. (2019, May 25). Adrenaline rush – symptoms: Causes: Effects: How to stop. Adrenaline Rush – Symptoms | Causes | Effects | How to Stop |. Retrieved December 8, 2022, from
  6. Greene, B. H. C., Lalonde, D. H., & Seal, S. K. F. (2021). Incidence of the “Adrenaline Rush” and Vasovagal Response with Local Anesthetic Injection. Plastic and reconstructive surgery. Global open, 9(6), e3659.
  7. Can stress cause vision problems? The Optometry Center for Vision Therapy. (2019, October 18). Retrieved December 8, 2022, from
  8. da Silva Castanheira, K., LoParco, S. & Otto, A.R. Task-evoked pupillary responses track effort exertion: Evidence from task-switching. Cogn Affect Behav Neurosci 21, 592–606 (2021).


Picture Courtesy

  1. Figure 1: Ghosh D, 2022, My two eyes were full of ways…. If you fly in the wind, the cowardly area…, Instagram, accessed 09 December 2022, < >.
  2. Figure 2: This figure has been created by author.