City Research Online

Abstract

The advancement in adaptive optics in recent years has increased the interest in the dynamic aberrations of the eye, including those introduced by the first optical surface provided by the tear film. A curvature sensing system to measure the dynamic topography of the tear film is described. This optical system was used to measure the aberrations of the tear film on 14 eyes. The evolution of this surface is monitored through videos of the tear film topography. The effect on optical quality is studied from the time-evolution of the RMS wavefront error showing non-negligible aberration variations attributed to the tear film layer; the effect of tear film break-up on the ocular optical quality is also discussed. Furthermore, the aberration maps are decomposed into their constituent Zernike components showing stronger contributions from 4th order terms, and also from those components with vertical symmetry which can be attributed to the effect of the eye lids on the tear film. Finally, the power spectra of the RMS wavefront error evolution show that the strongest contributions of the tear film aberrations are to be found at low frequencies, typically below 2Hz.

Publication Type:	Article
Subjects:	R Medicine > RE Ophthalmology
Departments:	School of Health & Psychological Sciences > Optometry & Visual Sciences

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