Image created using OpenAI

Romantics say that the eyes are windows into the soul. Over time, researchers have come to learn this to be true on another level: the eyes are windows into the health of the body. And more recently, they’ve added ears to that equation as well! While not very romantic, that scientists are tapping into our senses to gain insight into what’s happening in other areas of the body is opening up new frontiers to disease detection. Specifically, researchers are examining the role saccades — rapid eye movements — play in neurological disorders like Alzheimer’s.

Simply put, saccades shift the focus of gaze from one point to another. They are a fundamental aspect of visual processing, enabling quick scanning of the environment and bringing new areas of interest into the high-resolution central part of the retina (the fovea). Extremely fast, saccades typically range from 30 to 500 degrees per second and are short-lived, often lasting only 20 to 200 milliseconds. They help collect visual information efficiently by moving between fixations (moments when the eye is relatively still and detailed visual information is processed). Researchers measure saccades with eye-tracking devices that record the speed, direction, and amplitude of eye movements.

When the saccades behave abnormally, it may be because of diseases like Alzheimer’s, Parkinson’s, Multiple Sclerosis, or Huntington’s. Concussion and Traumatic Brain Injuries (TBI) will often cause changes in the saccadic reaction times as well, giving doctors a warning into what’s going on with the brain, leading to better treatment outcomes.

Besides eye-tracking devices, which are not accessible to everyone, researchers at Dartmouth University and the Laboratory at École de Technologie Supérieure have recently begun using hearing devices called “hearables,” which can pick up eardrum vibrations created by saccades and provide more accessible information and data, leading to better detection of neurological problems for patients.