Diagnostic examination

Penrith Spectacles now have the i.Profiler® plus, an instrument from Zeiss that allows us to make your glasses even better! Technical details are below, but basically the i.Profiler® plus allows us to measure aberrations of the eye, and compensate for them in your spectacles. At the time of page preparation, we have the only one in Sydney.

Aberrations are fine optical imperfections that are found in all kinds of optical systems. Optical designers and optometrists have known about them for a long time. James Maxwell and Ernst Abbe in the 1850s described aberrations. Frits Zernicke in the 1930s described aberrations in such a way that they could be separated from each other. The i.Profiler® plus analyses the pattern, called a wavefront, that light makes leaving your eye, and performs a Zernicke analysis of the results.

Wavefront aberrometers have been used on eyes for 20 years, initially in research, and later in laser corrective eye surgery. Early laser practitioners found that some patients could read the bottom lines on eye charts, but were still unhappy with their vision, with glare problems or difficulty at night or in low contrast situations. Wavefront results are now used to modify the curves put on the eye by the laser, with generally excellent results.

So, if aberrations have been known about for so long, what has been done about them? In systems like cameras and telescopes, multiple lenses are combined to minimise aberrations. In spectacles, lenses are made in meniscus form, so the front curves out, and the back in, to minimise aberrations. That’s all very well, but you only have one lens in front of your eye, and no attempt has been made to use the lens to minimise the eye’s aberration.

The i.Profiler® plus lets Penrith Spectacles send the results of the wavefront analysis, along with the conventional spectacle prescription, to the computer controlled machine used to make your lenses. This i.Scription® means your lenses are made to minimise the aberrations not just of the spectacle lens, but of the optical system made up of your spectacles and your eye, giving you the best image possible on your retina. with increased sharpness and minimum glare.

Does it work for everybody? Of course not. Some eyes naturally have very low aberrations. Some eyes have other problems, optically or medically, that mean an i.Scription® is not for you. The i.Profiler® plus, in conjunction with our optometrist, will advise you if this is the case.