A method for determining aberrations in the eye of a subject, comprising: performing a sequential objective wavefront analysis of the residual aberration in the vision of the eye and a subjective phoropter measurement, using the objectively measured aberrations to adjust settings of vision correction elements in the subjective phoropter measurement, by: providing a measurement system incorporating: a phoropter disposed in front of the eye of the subject, such that the vision of the eye of the subject can be subjectively corrected; and a wavefront analyzer for determining objectively the aberrations of the eye of the subject, said wavefront analyzer being disposed such that light emitted from said eye enters said wavefront analyzer after traversing said phoropter; performing a first objective measurement of said eye using said wavefront analyzer; adjusting the settings of said phoropter to correct the aberrations of said eye as measured by said first objective measurement; performing a first subjective correction of the vision of said eye using said phoropter; performing a second objective measurement of said eye using said wavefront analyzer, to determine the aberrations of said eye after said first subjective correction by said phoropter; readjusting the settings of said phoropter to correct the aberrations of said eye as measured by said second objective measurement; performing a second subjective correction of the vision of said eye using said phoropter with said readjusted settings; determining whether the number of iterative steps has exceeded a predetermined number and if so outputting the last phoropter setting as the optimum prescription; if the number of iterative steps has not exceeded said predetermined number, determining the residual aberration detected at the last objective wavefront analysis, and if less than a predetermined level, outputting the last phoropter setting as the optimum prescription; and if the residual aberration detected at the last objective wavefront analysis is more than said predetermined level, continuing with said iterative objective and subjective measurements. providing a measurement system incorporating: a phoropter disposed in front of the eye of the subject, such that the vision of the eye of the subject can be subjectively corrected; and a wavefront analyzer for determining objectively the aberrations of the eye of the subject, said wavefront analyzer being disposed such that light emitted from said eye enters said wavefront analyzer after traversing said phoropter; a phoropter disposed in front of the eye of the subject, such that the vision of the eye of the subject can be subjectively corrected; and a wavefront analyzer for determining objectively the aberrations of the eye of the subject, said wavefront analyzer being disposed such that light emitted from said eye enters said wavefront analyzer after traversing said phoropter; performing a first objective measurement of said eye using said wavefront analyzer; adjusting the settings of said phoropter to correct the aberrations of said eye as measured by said first objective measurement; performing a first subjective correction of the vision of said eye using said phoropter; performing a second objective measurement of said eye using said wavefront analyzer, to determine the aberrations of said eye after said first subjective correction by said phoropter; readjusting the settings of said phoropter to correct the aberrations of said eye as measured by said second objective measurement; performing a second subjective correction of the vision of said eye using said phoropter with said readjusted settings; determining whether the number of iterative steps has exceeded a predetermined number and if so outputting the last phoropter setting as the optimum prescription; if the number of iterative steps has not exceeded said predetermined number, determining the residual aberration detected at the last objective wavefront analysis, and if less than a predetermined level, outputting the last phoropter setting as the optimum prescription; and if the residual aberration detected at the last objective wavefront analysis is more than said predetermined level, continuing with said iterative objective and subjective measurements.