Apart from improved ability focus ability and vision clarity, does LASIK surgery produce any perceptible changes or artifacts to vision?

You are right that visual acuity is not the sum total of measuring visual function in the eye. Eye charts are typically totally black letters against a bright white background -100% contrast. But the real world is mostly moderate to low contrast -browns against Grays; navy blue against black; golf balls against white clouds, etc.

The object of LASIK is not just to "improve your vision" if vision is thought of only in terms of visual acuity on eye charts (refraction). It is to optimize all of the optical aberrations (causes of blur) on the corneal surface. This can be done with the most technologically advanced lasers based on corneal contour and wavefront measurements of visual function. When such subtle but important aspects of vision such as irregular astigmatism, spherical aberration and coma can be treated simultaneously with treating the myopia (nearsightedness) and regular astigmatism, the resulting visual function can and should be better than what glasses and even contact lenses can provide. If not, one can have to deal with ghost images, halos at night, and other disturbing flaws in one's vision.

_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic