In one embodiment, an apparatus for optimizing vision correction procedures comprising: a 
narrow beam of light directed to a patient's 
retina; a dynamic defocus and compensation offsetting device configured to offset the defocus of a 
wavefront from an eye, a 
wavefront sensor configured to measure the local tilt of a number of subwavefronts sampled around an annular ring (the 
diameter of which can be dynamically changed) over the 
wavefront with the defocus offset; and a 
display device configured to display a two dimensional (2D) data points pattern in real time with each 
data point location representing a corresponding local tilt of the sampled subwavefronts. A proper defocus offset, not passive compensation, can reveal the predominant feature(s) of other 
wavefront aberration component(s), thus enabling a refractive surgeon to fine tune the vision correction procedure and minimize the remaining 
wavefront aberration(s) in real time. Meanwhile, by sampling the wavefront around annular rings and displaying the local tilt of the sampled subwavefronts on a monitor in the form of a 2D data points pattern, a refractive ophthalmic surgeon can easily correlate the measurement result to the two major refractive errors, namely spherical and cylinder refractive errors, including the axis of 
astigmatism.