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Forward light scatter analysis of the eye in a spatially-resolved double-pass optical system.

Nam J, Thibos LN, Bradley A, Himebaugh N, Liu H - Opt Express (2011)

Bottom Line: An optical analysis is developed to separate forward light scatter of the human eye from the conventional wavefront aberrations in a double pass optical system.We prove an additivity property for radial variance that allows us to distinguish between spot blurs from macro-aberrations and micro-aberrations.When the method is applied to tear break-up in the human eye, we find that micro-aberrations in the second pass accounts for about 87% of the double pass image blur in the Shack-Hartmann wavefront aberrometer under our experimental conditions.

View Article: PubMed Central - PubMed

Affiliation: School of Optometry, Indiana University, 800 Atwater Avenue, Bloomington, Indiana 47405, USA. jnam@indiana.edu

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The raw image of the SH spots encircled with a pupil of radius 3 mm. The diameter of each lenslet is 400 microns in the SH detector. We expect a 15x15 array of the spot images inside the pupil. The ' + ' sign indicates the pupil center, which does not necessarily coincide with a spot in a lenslet. The intensity of the raw images was boosted for the display purpose. (a) the baseline data when the tear film forms a smooth surface (soon after ablink), (b) the SH image after the tear break-up (following blink-suppression).
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g007: The raw image of the SH spots encircled with a pupil of radius 3 mm. The diameter of each lenslet is 400 microns in the SH detector. We expect a 15x15 array of the spot images inside the pupil. The ' + ' sign indicates the pupil center, which does not necessarily coincide with a spot in a lenslet. The intensity of the raw images was boosted for the display purpose. (a) the baseline data when the tear film forms a smooth surface (soon after ablink), (b) the SH image after the tear break-up (following blink-suppression).

Mentions: The raw SH spot images g were acquired from human eyes by a 633 nm laboratory aberrometer [10]. The lenslet diameter was 400 microns referenced in the eye’s pupil with the telescope magnification of 1. The camera resolution was 6.8 micron per pixel producing a 59x59 pixel window for each lenslet image. When the tear film forms a smooth surface, individual raw spot images are well focused and appear in a regular array as shown in Fig. 7(a)Fig. 7


Forward light scatter analysis of the eye in a spatially-resolved double-pass optical system.

Nam J, Thibos LN, Bradley A, Himebaugh N, Liu H - Opt Express (2011)

The raw image of the SH spots encircled with a pupil of radius 3 mm. The diameter of each lenslet is 400 microns in the SH detector. We expect a 15x15 array of the spot images inside the pupil. The ' + ' sign indicates the pupil center, which does not necessarily coincide with a spot in a lenslet. The intensity of the raw images was boosted for the display purpose. (a) the baseline data when the tear film forms a smooth surface (soon after ablink), (b) the SH image after the tear break-up (following blink-suppression).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368325&req=5

g007: The raw image of the SH spots encircled with a pupil of radius 3 mm. The diameter of each lenslet is 400 microns in the SH detector. We expect a 15x15 array of the spot images inside the pupil. The ' + ' sign indicates the pupil center, which does not necessarily coincide with a spot in a lenslet. The intensity of the raw images was boosted for the display purpose. (a) the baseline data when the tear film forms a smooth surface (soon after ablink), (b) the SH image after the tear break-up (following blink-suppression).
Mentions: The raw SH spot images g were acquired from human eyes by a 633 nm laboratory aberrometer [10]. The lenslet diameter was 400 microns referenced in the eye’s pupil with the telescope magnification of 1. The camera resolution was 6.8 micron per pixel producing a 59x59 pixel window for each lenslet image. When the tear film forms a smooth surface, individual raw spot images are well focused and appear in a regular array as shown in Fig. 7(a)Fig. 7

Bottom Line: An optical analysis is developed to separate forward light scatter of the human eye from the conventional wavefront aberrations in a double pass optical system.We prove an additivity property for radial variance that allows us to distinguish between spot blurs from macro-aberrations and micro-aberrations.When the method is applied to tear break-up in the human eye, we find that micro-aberrations in the second pass accounts for about 87% of the double pass image blur in the Shack-Hartmann wavefront aberrometer under our experimental conditions.

View Article: PubMed Central - PubMed

Affiliation: School of Optometry, Indiana University, 800 Atwater Avenue, Bloomington, Indiana 47405, USA. jnam@indiana.edu

Show MeSH
Related in: MedlinePlus