Refractive surgery encompasses a very wide range of procedures which primarily aim to reduce the spectacle dependence of patients. Safety profile of these surgeries is excellent and they have given extremely reproducible results over the years. As with any other surgery, the outcomes depend upon patient selection and selection of the right procedure. “One size does not fit all” and that’s why we recommend any surgical procedure after thorough evaluation of our patients.
With that being said let us explain what is the meaning of “reduced spectacle dependence”. Our vision has two primary constituents namely quality of vision (Contrast sensitivity) and quality of vision (Visual acuity). What any optometrist measures when they ask a person to read the Snellen’s chart (chart with many alphabets written on it) is the quantitative assessment. So 6/6 vision is 100 percent of that of a normal population. Now this 100 percent is calculated by taking an average of vision of thousands and thousands of normal patients of which, many will be better that 6/6 (6/5 or 6/4) and many will be worse (6/9 or 6/12). The normal individuals having lesser than 6/6 vision practically have no problems in their day to day life because their optical requirement is not same as that of a pilot or a surgeon. So similar analogy applies to results after any laser vision correction surgery. All patients undergoing spectacle correction surgery may not achieve 6/6 vision but almost 90% (see reference below) patients hold a vision of 6/12 or better after 10 years of lasik surgery. And as we have seen that 6/12 in either eye separately translates almost to 6/9 with both eyes, which is very well within the range of spectacle free result after 5 years of surgery. Some of the patients may need spectacle if they wish to read very fine prints from far off, like small prints in television etc but most people will not have any difficulty.