Dr. Vengu Lakshminarayanan
Many visual functions decline with age. As people grow older, for example, they need glasses to read due to changes in the eye’s lens. School of Optometry professor Vasudevan (Vengu) Lakshminarayanan is interested in less-common phenomena: visual functions that don’t change with age.
Interdisciplinary researcher looks at aging vision
Many visual functions decline with age. As people grow older, for example, they need glasses to read due to changes in the eye’s lens. School of Optometry professor Vasudevan (Vengu) Lakshminarayanan is interested in less-common phenomena: visual functions that don’t change with age.
Holding cross-appointments in the electrical and computer engineering and the physics and astronomy departments, the free-ranging academic — though primarily a theorist — uses psychophysics (the science of quantifying perceptual phenomena and processes) experiments to explore the limits of visual performance.
In what is known as the Stiles-Crawford effect, the eye is more sensitive to light coming in through the centre than through the periphery. This response function is related to how the photoreceptor cells, the rods and cones on the retina, are oriented.
It turns out,” says Lakshminarayanan, “that directional sensitivity does not change with age.”
Hyperacuity, the recognition of relative position of two or more objects — “like lining up the ends of two lines so that they touch precisely” — is another function that defies aging.
By carefully choosing experimental paradigms, researchers can attempt to quantify how the two tasks are performed,” he explains.
Determining what changes with age and what stays the same could be helpful in answering such questions as how long a person can safely continue to drive. Identifying an individual’s abnormal responses in one or more of these functions could be used to diagnose illness or eye disease more accurately and to monitor the efficacy of treatment and/or progression of the disease.
An adjunct professor at the School of Optometry in the late 1990s, Lakshminarayanan has returned to Waterloo, in part because of the potential for interdisciplinary collaboration. He serves on the editorial board of a number of publications reflecting his international focus and is a member of the UNESCO working group on active learning in optics and photonics, as well as a member of the National Academy of Science (USA) International Union of Pure and Applied Physics committee.
- More information about Dr. Vengu Lakshminarayanan
- School of Optometry and Vision Science
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