As someone steps into a dimly lit room, their eyes adapt slowly to the dark, temporarily affecting their vision, according to Wen Shen, Ph.D. But for older adults, or those with vision ailments, that adaption process takes much longer, potentially creating an unstable situation.
That’s why Shen, supported by a $500,000 grant from the National Science Foundation, is researching how eyes adapt during varied light conditions with the aim of developing treatment strategies that could help eyes improve when switching from dim to brighter lights.
Specifically, Shen looks at the retina inside the eye, and how neurons like photoreceptors in the retina — a layer of tissue in the back of your eye that senses light and sends images to your brain — communicate with another neuron as the eyes adjust to bright or dim lights.
“When the eyes adapt during dark or light situations, the retinas inside the eye adjust to lesser or greater levels of light in the environment,” she said. “However, with light-sensitive problems or diseases, the adaptation functions in the eyes decline progressively.”
To effectively intervene in the visual functional impairment, scientists need to understand the retina’s neural circuitry and functions of the neural chemicals involved in the adaptation process, she added.
Shen has discovered that a chemical called glycine, might play an important role to help eyes improve adapting faster.
“People don’t think about how to adjust one’s vision performance in dim light or lower light conditions or if it’s needed at all, but it is,” she said. “By understanding how normal neurons function and the physiology of the retina, it helps me understand when something goes wrong in the eyes, and it enables more effective treatment plans for people with abnormal vision or diseases found in the retina.”
So far, Shen said, the glycine has been shown to balance the neurons while improving visual sensitivity.
This method she hopes will aid in the rehabilitation process with those who lose sensitivity and have trouble determining light from dark. Shen’s grant also seeks to integrate research and education, updating the way student researchers learn and understand neurons in the retina, she said.
“We’ve discovered something unique here and it’s just the beginning,” she said. “The more knowledge and information we discover about the adaptation process in the eyes, the more we can determine which part of the neurons are suffering and find better methods for diagnosing and treating patients throughout South Florida.”