Vision Experts Don't See Eye to Eye in Quest for Perfect Sight
Thibos says that there are factors in the eye that can vary over the short or long term, such as changes in the ability of the lens to compensate for changes in near and far vision (an ability that declines with age), tear-flow irregularities, and abnormalities in how we see colors. All of these things may ultimately affect the quality of the retinal image.
In addition, even if "perfect" retinal images are achievable, the end user -- the patient -- may be unhappy with the results. Thibos points out that computer monitors, television screens, and the printed page all take advantage of the fact that our eyes can't perfectly discriminate fine details such as pixels, scan lines, or dots of ink, and instead blend the images into seemingly sharp pictures.
Ultimately, though, Kornmehl says, patients and eye surgeons might be better served by remembering that "perfect" is often the enemy of "good."
"There's no guarantee of perfection," he tells WebMD. "Many people say we've improved their lives, they're happy and they're thrilled and it enriches their lives tremendously, but if people are looking for perfection -- far, near, close, forever -- no, of course not. It's wonderful what we're doing, but people have to maintain a certain perspective as well."