Police can see adequately to do their work after eye surgery: UW study
November 16, 2006
Source: University of Waterloo
WATERLOO, Ont. (Thursday, Nov. 16, 2006) -- Police officers and recruits who have undergone eye surgery can on average see adequately enough to do the work that's expected of them, a University of Waterloo optometry study has concluded.
The study, published in the November issue of American Journal of Industrial Medicine, looks at whether visual performance of police officers and candidates who have undergone refractive surgery was actually worse than the non-surgical control officers and candidates.
"Refractive surgery remains a controversial topic for law enforcement agencies because the vision of officers who have had refractive surgery may be impaired in low-light levels," said Dr. Jeff Hovis, a UW optometry professor who led the study.
Refractive surgery seeks to improve the refractive state of the eye and decrease dependency on glasses or contact lenses. The most common methods use lasers to reshape the cornea. Successful refractive eye surgery can help to reduce such common vision disorders as myopia, hyperopia and astigmatism.
In the study, visual performance was assessed using high- and low-contrast letters and numbers in both bright- and dim-light conditions. Sensitivity to glare in low-light levels was also assessed.
The study's general findings were that the refractive surgery group had slightly lower acuity scores for the low-contrast targets in both room- and dim-light levels, together with an increased sensitivity to glare.
"Although refractive surgery police recruits and officers had reduced performance on some vision tests, these reductions were small and it is unlikely that their performance on vision-related tasks would be compromised on average," Hovis said.
He said the major concern was the small number of refractive surgery officers whose results were well outside the range of the non-surgical candidates.
As well, the study raised the issue of whether low-light level vision standards should be established to ensure that all refractive surgery candidates have adequate vision in low-light levels. The control group consisted of 76 officers and recruits who did not have refractive surgery while the refractive surgery group consisted of 22 officers and recruits.
In his research, Hovis studies the area of occupational vision. His interests cover the effects that congenital color vision deficiencies have on job-related performance, as well as the functional impact of protective eyewear for the military.
He also explores the basic mechanisms of normal and abnormal human color perception and evaluating various clinical color vision tests.