 OD PhD FAAO, Greeman-Petty Professorship in Vision Development
and Dean of the College of Optometry, University of Houston
Professor Earl Smith III has been reshaping the way we think about our eyes for most of his career. In particular, our understanding of Myopia has been revolutionised by his insights. His primary research interests are focused on the optics of the eye, especially on the environmental and physiological factors that influence the eye’s refractive status. In 1996, he received the Glenn Fry Award from the American Academy of Optometry for his research on the role of vision in regulating refractive development and eye growth.
Prof Smith has published over 150 refereed papers and received 28 years of research funding from the National Institute of Health’s (NIH) National Eye Institute (NEI). He is also an accomplished lecturer and a past Texas Optometric Association Educator of the Year.
Prof Smith is a past President of the American Optometric Foundation (2002) and currently serves on the Board of Directors of Prevent Blindness Texas, Board of Directors of the Partnership Foundation for Optometric Education and is President-Elect of the Association of Schools and Colleges of Optometry.
Abstract
The dramatic increases in myopia taking place around the globe suggest that changing environmental factors are influencing the current pattern of refractive errors. This also emphasizes the need for an effective optical treatment strategy to reduce the public health impact of this common disorder.
The discovery that ocular growth and refractive development are regulated by visual feedback promised to result in new optical treatment strategies for myopia. However, most attempts to prevent the onset and progression of myopia have failed, primarily because our assumptions concerning the operating characteristics of the vision-dependent mechanisms that regulate refractive development have been wrong and have interfered with our attempts to develop effective anti-myopia therapies.
For example, because of the prominence of central vision, it has generally been assumed that signals from the fovea dominate the effects of vision on refractive development and almost all attempts to retard the development of myopia have involved manipulating central vision and the nature of the foveal image.
However, our experiments demonstrate that the effects of visual experience on eye shape and refractive development are mediated primarily by local, regionally selective mechanisms and that foveal vision is not essential for many of the vision-dependent aspects of refractive development. On the other hand, the peripheral retina, in isolation, can effectively regulate ocular growth and emmetropization and mediate many of the effects of vision on the eye’s refractive status.
Moreover, when there are conflicting visual signals between the fovea and the periphery, refractive development is dominated by peripheral vision. The overall pattern of results suggests that optical treatment strategies that focus only on manipulating central vision will have limited impact and that those treatment strategies that are directed at the periphery are more likely to be successful. Moreover, peripheral treatment strategies can have therapeutic anti-myopia effects without interfering with central visual acuity. |
