The billion dollar Hubble Telescope has been assisting astronomers for nearly two decades now, gathering information about our own Milky Way galaxy and the rest of our universe. The entire project has not been without problems, however. Shortly after its launch in 1990, it was discovered that the mirror contained significant spherical aberration that affected the performance of the telescope. A system was developed called COSTAR, Corrective Optics Space Telescope Axial Replacement, which used two mirrors in the light path to correct for the aberration in the main mirror. With this adaptation, astronomers could achieve the accuracy and clarity that they were hoping for.
Adaptive optics relies upon a secondary set of mirrors that are in place to adjust for errors within the main optical system. While the Hubble is one example of this, our own eyes can benefit from the advances made through adaptive optics. The measured point spread function in our eyes is far from perfect. In people with keratoconus and other corneal diseases, these optical error are even more significant. It is possible, however, to reflect light through a mirror that adapts light to these optical errors and produce a clearer picture on the retina.
Deformable mirrors (DM’s) have become very important for this. Once a person’s point spread function is measured, a deformable mirror can adapt itself to these measurements. In modern LASIK surgery, surgeons are measuring patient’s point spread functions in order to customize the LASIK surgery to improve vision results. In keratoconus treatment, the progress of the disease can be tracked through the measurements of a patients “wavefront” or point spread function. In cataract surgery, newer lenses are using principles of optics to provide clearer vision through adaptive optics. Doctors can also use adaptive optics to view the back of a patient’s eye, the retina. In fact, adaptive optics now allows researchers to view individual photoreceptors in a live human eye.
As research continues, we expect to see greater improvement in the application of adaptive optics. Perhaps LASIK surgery will continue to improve or adjustments can be made to allow LASIK to correct not just myopia, hyperopia, and astigmatism but top also decrease the symptoms of presbyopia. Many companies are looking at multifocal or aspheric corrections with LASIK surgery. Researchers are using adaptive optics to measure the extent of the vision loss in keratoconus that is caused by the cornea and how much is caused by loss of neural information. The field of adaptive optics appears to be able to provide many new and interesting discoveries. Keratoconus is one important disease that stands to benefit from the advances in research of adaptive optics.