Reassessment of Fisher's (1971) Spinning Lens Test (2004-2006)
Dr Harvey Burd, Dr Stuart Judge and Mr Geoffrey Wilde
Although there is considerable current interest in the
development of procedures to correct for presbyopia, there is considerable
uncertainty in the detailed physiological causes of the decline in accommodation
amplitude with age.
It is generally thought that increases in lens stiffness with age are
the principal cause of presbyopia. However, detailed studies of this
hypothesis are hampered by the lack of detailed and consistent experimental
data on lens stiffness. In an influential paper, Fisher (1971) described
a spinning lens experiment to determine lens stiffness. However, several
features of Fisher's data remain puzzling.
Research has been completed on a detailed theoretical investigation
of Fisher's test. An preliminary experimental study, based on Fisher's spinning lens
concept, has also been completed. The photograph, below, shows a porcine
lens being tested in a spinning lens test rig that has recently been
constructed at Oxford University.
Porcine lens in the spinning lens rig
The results of a re-evaluation of Fisher's original results are given in Burd et al. (2005) and Burd et al. (2006).
Publications
- Burd, H.J., Wilde, G.S. and Judge, S.J. (2006) "Can reliable values of Young's modulus be deduced from Fisher's (1971) spinning lens measurements?" Vision Research, 46(8-9), 1346-1360.
- Burd, H.J., Wilde, G.S. and Judge, S.J. (2005) "A reassessment of Fisher's spinning lens test" EVER abstract No. 4322.