One of the greatest and most reliable technological advances in refraction (determining the correction of the visual system) has been the OPD scan (for Optical Path Difference) that the office has recently acquired. It is an aberrometer, which allows us to perform an assessment of each patient's focussing system at levels never before possible. The OPD scan assesses how light focusses through every optical element of the eye, allowing us to isolate areas that may be causing problems with ones vision. This custom wavefront analysis is automatically performed on every patient. In addition, it performs a day and night vision assessment to determine if there are any significant differences in ones prescription during the day and during nightime conditions. In some cases, prescriptions during these different light conditions can be so different that different corrective lenses may be required for day versus night.
In addition, ocular disease management can be taken to a whole new level. Cataracts, corneal disease, pupil abnormalities, eyelid conditions, and surgical intraocular lens complications are only some of the conditions that can be monitored.
With this remarkable instrument, we can now evaluate a patient's total visual system. It allows us to measure both low (what we have typically been measuring in an eye exam) and high-order aberrations (what is "hiding under the surface" which we had typically not been able to see and measure). We now have the power to diagnose patient complaints that simply would not have been diagnosed before.
See the clip at: http://www.marco.com/videos/hd.html