Refractive index distribution and optical properties of the isolated human lens measured using magnetic resonance imaging (MRI).
Using a non-invasive MRI technique for measuring the refractive index distribution through the crystalline lens, refractive index maps were obtained through 20 intact isolated human lenses (7-82years). Focal length measurements, obtained by simulated light ray propagation through each index map were found to be in agreement with direct measurements performed on a scanning laser apparatus. With increasing age, the refractive index profiles became flatter in the central region, accompanied by steepening of the profile in the periphery. This appears to be an important mechanism underlying the observed changes in power and longitudinal aberration of the human lens.
School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, 2 George St., Brisbane 4001, Australia.
C E
CE
Jones
D A
DA
Atchison
R
R
Meder
J M
JM
Pope
D000328:Adult; D000367:Age Factors; D000369:Aged, 80 and over; D002138:Calibration; D002648:Child; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007834:Lasers; D007908:Lens, Crystalline / Q000033:anatomy & histology / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D055095:Optics and Photonics; D010775:Photic Stimulation; D012029:Refraction, Ocular / Q000502:physiology*