Limits...
Design and validation of a scanning Shack Hartmann aberrometer for measurements of the eye over a wide field of view.

Wei X, Thibos L - Opt Express (2010)

Bottom Line: The prototype SSHA successfully measured the off-axis wavefront aberrations over +/- 15 degree visual field within 7 seconds.In two validation experiments with a wide angle model eye, it measured change in defocus aberration accurately (<0.02microm, 4mm pupil) and precisely (<0.03microm, 4mm pupil).A preliminary experiment with a human subject suggests its feasibility in clinical applications.

View Article: PubMed Central - PubMed

Affiliation: School of Optometry, Indiana University, Bloomington, Indiana 47405, USA. weix@indiana.edu

ABSTRACT
Peripheral vision and off-axis aberrations not only play an important role in daily visual tasks but may also influence eye growth and refractive development. Thus it is important to measure off-axis wavefront aberrations of human eyes objectively. To achieve efficient measurement, we incorporated a double-pass scanning system with a Shack Hartmann wavefront sensor (SHWS) to develop a scanning Shack Hartmann aberrometer (SSHA). The prototype SSHA successfully measured the off-axis wavefront aberrations over +/- 15 degree visual field within 7 seconds. In two validation experiments with a wide angle model eye, it measured change in defocus aberration accurately (<0.02microm, 4mm pupil) and precisely (<0.03microm, 4mm pupil). A preliminary experiment with a human subject suggests its feasibility in clinical applications.

Show MeSH
Scanning pattern of SSHA apparatus. As the scanning mirrors rotate, the mirrors direct the beam along different LoS in sequence. Each data point in the figure indicates a particular LoS in test eyes’ object space. The associated numbers represent the sequential order. It took 8 seconds for SSHA to scan the whole visual field.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3369549&req=5

g002: Scanning pattern of SSHA apparatus. As the scanning mirrors rotate, the mirrors direct the beam along different LoS in sequence. Each data point in the figure indicates a particular LoS in test eyes’ object space. The associated numbers represent the sequential order. It took 8 seconds for SSHA to scan the whole visual field.

Mentions: Scanning Shack Hartmann aberrometer (SSHA) apparatus. BS1-3, beam splitters; DPS1-4, Double pass scanning lenses; L5-9, Lenses; SHWS, Shack Hartmann Wavefront sensor; Aperture A1, limiting aperture.


Design and validation of a scanning Shack Hartmann aberrometer for measurements of the eye over a wide field of view.

Wei X, Thibos L - Opt Express (2010)

Scanning pattern of SSHA apparatus. As the scanning mirrors rotate, the mirrors direct the beam along different LoS in sequence. Each data point in the figure indicates a particular LoS in test eyes’ object space. The associated numbers represent the sequential order. It took 8 seconds for SSHA to scan the whole visual field.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369549&req=5

g002: Scanning pattern of SSHA apparatus. As the scanning mirrors rotate, the mirrors direct the beam along different LoS in sequence. Each data point in the figure indicates a particular LoS in test eyes’ object space. The associated numbers represent the sequential order. It took 8 seconds for SSHA to scan the whole visual field.
Mentions: Scanning Shack Hartmann aberrometer (SSHA) apparatus. BS1-3, beam splitters; DPS1-4, Double pass scanning lenses; L5-9, Lenses; SHWS, Shack Hartmann Wavefront sensor; Aperture A1, limiting aperture.

Bottom Line: The prototype SSHA successfully measured the off-axis wavefront aberrations over +/- 15 degree visual field within 7 seconds.In two validation experiments with a wide angle model eye, it measured change in defocus aberration accurately (<0.02microm, 4mm pupil) and precisely (<0.03microm, 4mm pupil).A preliminary experiment with a human subject suggests its feasibility in clinical applications.

View Article: PubMed Central - PubMed

Affiliation: School of Optometry, Indiana University, Bloomington, Indiana 47405, USA. weix@indiana.edu

ABSTRACT
Peripheral vision and off-axis aberrations not only play an important role in daily visual tasks but may also influence eye growth and refractive development. Thus it is important to measure off-axis wavefront aberrations of human eyes objectively. To achieve efficient measurement, we incorporated a double-pass scanning system with a Shack Hartmann wavefront sensor (SHWS) to develop a scanning Shack Hartmann aberrometer (SSHA). The prototype SSHA successfully measured the off-axis wavefront aberrations over +/- 15 degree visual field within 7 seconds. In two validation experiments with a wide angle model eye, it measured change in defocus aberration accurately (<0.02microm, 4mm pupil) and precisely (<0.03microm, 4mm pupil). A preliminary experiment with a human subject suggests its feasibility in clinical applications.

Show MeSH