Abstract

Realistic simulation of ophthalmic measurements on normal and diseased eyes is presented. We use clinical data of ametropic and keratoconus patients to construct anatomically accurate three-dimensional eye models and simulate the measurement of a streak retinoscope with all the optical elements. The results show the clinical observations including the anomalous motion in high myopia and the scissors reflex in keratoconus. The demonstrated technique can be applied to other ophthalmic instruments and to other and more extensively abnormal eye conditions. It provides promising features for medical training and for evaluating and developing ocular instruments.

© 2007 Optical Society of America

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References

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  1. A. Gullstrand, "The Optical System of the Eye," in Physiological Optics, 3rd ed., H. von Helmholtz (Hamburg, Voss, 1909), Vols. 1 and 2, pp. 350-358.
  2. H. Von Helmholtz, Physiological Optics, 3rd ed. (Hamburg, Voss, 1909), Vols. 1 and 2, pp. 91-121.
  3. Y. Le Grand, Optique physiologique. T. 1. Dioptrique de l’oeil er sa correlations. English translation by S. G. el Hage. (Berlin, Springer-Verlag, 1980), pp. 64-67.
  4. W. Lotmar, "Theoretical eye model with aspherics," J. Opt. Soc. Am. 16, 1522-1529 (1971).
    [CrossRef]
  5. R Navarro, J. Santamaria, and J. Bescos, "Accommodation-dependent model of the human eye with aspherics," J. Opt. Soc. Am. A 2, 1273-1278 (1985).
    [CrossRef] [PubMed]
  6. I. Escudero-Sanz and R. Navarro, "Off-axis aberrations of a wide-angle schematic eye model," J. Opt. Soc. Am. A,  16, 1881-1891 (1999).
    [CrossRef]
  7. S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
    [CrossRef] [PubMed]
  8. I. H. Al-Ahdali, M. A. El-Messiery, "Examination of the effect of the fibrous structure of a lens on the optical characteristics of the human eye: a computer-simulated model," Appl. Opt. 34, 5738-5745 (1995).
    [CrossRef] [PubMed]
  9. H. Liou and N. Brennan, "Anatomically accurate, finite model eye for optical modeling," J. Opt. Soc. Am. A 14, 1684-1695 (1997).
    [CrossRef]
  10. R. Navarro, L. Gonzalez, and J. L. Hernandez-Matamoros, "On the prediction of optical aberrations by personalized eye models," Optom Vision Sci. 83, 371-381 (2006).
    [CrossRef]
  11. Y.-L. Chen, B. Tan, K. Baker, J. W. L. Lewis, T. Swartz, Y. Jiang, and M. Wang, "Simulation of keratoconus observation in photorefraction," Opt. Express 14, 11477-11485 (2006).
    [CrossRef] [PubMed]
  12. S. MacRae, J. Schwiegerling, and R. W. Snyder, "Customized and low spherical aberration corneal ablation design," J. Refract. Surg. 15, S246-S248 (1999).
    [PubMed]
  13. M. Mrochen, C. Donitzky, C. Wullner, and J. Loffler, "Wavefront-optimized ablation profiles: theoretical background," J. Cataract Refractive Surg. 30, 775-785 (2004).
    [CrossRef]
  14. J. B. Almeida and A. M. Garcia, "Theoretical calculation of a contact lens thickness designed to correct the eye's monochromatic aberrations," Optom. Vision Sci. 82, 59-63 (2005).
  15. P. R. Preussner, J. Wahl, and D. Weitzel, "Topography-based intraocular lens power selection," J. Cataract Refractive Surg. 31, 525-33 (2005).
    [CrossRef]
  16. R. B. Bennett, Clinical Visual Optics, 3rd ed., (Butterworth-Heinemann, Oxford, 1998).
  17. J. I. Pascal, Modern Retinoscopy (Hatton, London, 1930).
  18. E. Landolt, "Methods of determination of the refraction and accommodation of the eye," in The Refraction and Accommodation of the Eye, C. M. Culver, ed. (Pentland, Edinburgh, 1886).
  19. W. Swaine, "Retinoscopy. I. General outline and symbols," Optician, April, 171-179 (1945).
  20. W. Swaine, "Retinoscopy. II. Basic theoretical principles," Optician, June, 335-339 (1945).
  21. W. Swaine, "Retinoscopy. III. Variation of illumination across the reflex," Optician, August, 35-40 (1945).
  22. W. Swaine, "Retinoscopy. IV. Variation of the reflex brightness with refractive error and pupil diameter," Optician, August, 71-74 (1945).
  23. A. Roorda and W. R. Bobier, "Geometrical technique to determine the influence of monochromatic aberration on retinoscope," J. Opt. Soc. Am. A,  13, 3-11 (1996).
    [CrossRef]
  24. M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
    [CrossRef]
  25. G. Smith and S. Haymes, "The streak retinoscopy pupil reflex in the presence of astigmatism," Ophthalmic Physiol. Opt. 23, 295-305 (2003).
    [CrossRef]
  26. J.-M. Gorrand, A. Alfieri, and J.-Y. Boire, "Diffusion of the retinal layers of the living human eye," Vision Res. 24,1097-1106 (1984).
    [CrossRef] [PubMed]
  27. G. J. van Blokland, "Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo," Vision Res. 26,495-500 (1986).
    [CrossRef] [PubMed]
  28. R. Röhler and F. Schmeilau, "Properties of isolated frog retinae in reflecting non-polarized and polarized light," Vision Res. 16,241-246 (1976).
    [CrossRef] [PubMed]
  29. I. M. Borish, Clinical refraction, 3rd ed. (Professional press, Chicago, 1970).
  30. H. C. Howland, "Retinoscopy of infants at a distance: limits of normal and anomalous reflexes," Vision Res. 18, 597-599 (1978).
    [CrossRef] [PubMed]
  31. D. O. Mutti, "Sources of normal and anomalous motion in retinoscopy," Opotom. Vision.Sci. 81, 663-672 (2004).
    [CrossRef]

2006 (3)

R. Navarro, L. Gonzalez, and J. L. Hernandez-Matamoros, "On the prediction of optical aberrations by personalized eye models," Optom Vision Sci. 83, 371-381 (2006).
[CrossRef]

Y.-L. Chen, B. Tan, K. Baker, J. W. L. Lewis, T. Swartz, Y. Jiang, and M. Wang, "Simulation of keratoconus observation in photorefraction," Opt. Express 14, 11477-11485 (2006).
[CrossRef] [PubMed]

M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
[CrossRef]

2005 (2)

J. B. Almeida and A. M. Garcia, "Theoretical calculation of a contact lens thickness designed to correct the eye's monochromatic aberrations," Optom. Vision Sci. 82, 59-63 (2005).

P. R. Preussner, J. Wahl, and D. Weitzel, "Topography-based intraocular lens power selection," J. Cataract Refractive Surg. 31, 525-33 (2005).
[CrossRef]

2004 (2)

M. Mrochen, C. Donitzky, C. Wullner, and J. Loffler, "Wavefront-optimized ablation profiles: theoretical background," J. Cataract Refractive Surg. 30, 775-785 (2004).
[CrossRef]

D. O. Mutti, "Sources of normal and anomalous motion in retinoscopy," Opotom. Vision.Sci. 81, 663-672 (2004).
[CrossRef]

2003 (1)

G. Smith and S. Haymes, "The streak retinoscopy pupil reflex in the presence of astigmatism," Ophthalmic Physiol. Opt. 23, 295-305 (2003).
[CrossRef]

2001 (1)

S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
[CrossRef] [PubMed]

1999 (2)

S. MacRae, J. Schwiegerling, and R. W. Snyder, "Customized and low spherical aberration corneal ablation design," J. Refract. Surg. 15, S246-S248 (1999).
[PubMed]

I. Escudero-Sanz and R. Navarro, "Off-axis aberrations of a wide-angle schematic eye model," J. Opt. Soc. Am. A,  16, 1881-1891 (1999).
[CrossRef]

1997 (1)

1996 (1)

1995 (1)

1986 (1)

G. J. van Blokland, "Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo," Vision Res. 26,495-500 (1986).
[CrossRef] [PubMed]

1985 (1)

1984 (1)

J.-M. Gorrand, A. Alfieri, and J.-Y. Boire, "Diffusion of the retinal layers of the living human eye," Vision Res. 24,1097-1106 (1984).
[CrossRef] [PubMed]

1978 (1)

H. C. Howland, "Retinoscopy of infants at a distance: limits of normal and anomalous reflexes," Vision Res. 18, 597-599 (1978).
[CrossRef] [PubMed]

1976 (1)

R. Röhler and F. Schmeilau, "Properties of isolated frog retinae in reflecting non-polarized and polarized light," Vision Res. 16,241-246 (1976).
[CrossRef] [PubMed]

1971 (1)

W. Lotmar, "Theoretical eye model with aspherics," J. Opt. Soc. Am. 16, 1522-1529 (1971).
[CrossRef]

1945 (4)

W. Swaine, "Retinoscopy. I. General outline and symbols," Optician, April, 171-179 (1945).

W. Swaine, "Retinoscopy. II. Basic theoretical principles," Optician, June, 335-339 (1945).

W. Swaine, "Retinoscopy. III. Variation of illumination across the reflex," Optician, August, 35-40 (1945).

W. Swaine, "Retinoscopy. IV. Variation of the reflex brightness with refractive error and pupil diameter," Optician, August, 71-74 (1945).

Al-Ahdali, I. H.

Alfieri, A.

J.-M. Gorrand, A. Alfieri, and J.-Y. Boire, "Diffusion of the retinal layers of the living human eye," Vision Res. 24,1097-1106 (1984).
[CrossRef] [PubMed]

Almeida, J. B.

J. B. Almeida and A. M. Garcia, "Theoretical calculation of a contact lens thickness designed to correct the eye's monochromatic aberrations," Optom. Vision Sci. 82, 59-63 (2005).

Baker, K.

Baraibar, B.

S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
[CrossRef] [PubMed]

Bescos, J.

Bobier, W. R.

Boire, J.-Y.

J.-M. Gorrand, A. Alfieri, and J.-Y. Boire, "Diffusion of the retinal layers of the living human eye," Vision Res. 24,1097-1106 (1984).
[CrossRef] [PubMed]

Brennan, N.

Burns, S. A.

S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
[CrossRef] [PubMed]

Caballero, M. T.

M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
[CrossRef]

Chen, Y.-L.

Donitzky, C.

M. Mrochen, C. Donitzky, C. Wullner, and J. Loffler, "Wavefront-optimized ablation profiles: theoretical background," J. Cataract Refractive Surg. 30, 775-785 (2004).
[CrossRef]

El-Messiery, M. A.

Escudero-Sanz, I.

Furlan, W. D.

M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
[CrossRef]

Garcia, A. M.

J. B. Almeida and A. M. Garcia, "Theoretical calculation of a contact lens thickness designed to correct the eye's monochromatic aberrations," Optom. Vision Sci. 82, 59-63 (2005).

Gonzalez, L.

R. Navarro, L. Gonzalez, and J. L. Hernandez-Matamoros, "On the prediction of optical aberrations by personalized eye models," Optom Vision Sci. 83, 371-381 (2006).
[CrossRef]

Gorrand, J.-M.

J.-M. Gorrand, A. Alfieri, and J.-Y. Boire, "Diffusion of the retinal layers of the living human eye," Vision Res. 24,1097-1106 (1984).
[CrossRef] [PubMed]

Haymes, S.

G. Smith and S. Haymes, "The streak retinoscopy pupil reflex in the presence of astigmatism," Ophthalmic Physiol. Opt. 23, 295-305 (2003).
[CrossRef]

Hernandez-Matamoros, J. L.

R. Navarro, L. Gonzalez, and J. L. Hernandez-Matamoros, "On the prediction of optical aberrations by personalized eye models," Optom Vision Sci. 83, 371-381 (2006).
[CrossRef]

Howland, H. C.

H. C. Howland, "Retinoscopy of infants at a distance: limits of normal and anomalous reflexes," Vision Res. 18, 597-599 (1978).
[CrossRef] [PubMed]

Jiang, Y.

Lewis, J. W. L.

Liou, H.

Loffler, J.

M. Mrochen, C. Donitzky, C. Wullner, and J. Loffler, "Wavefront-optimized ablation profiles: theoretical background," J. Cataract Refractive Surg. 30, 775-785 (2004).
[CrossRef]

Lotmar, W.

W. Lotmar, "Theoretical eye model with aspherics," J. Opt. Soc. Am. 16, 1522-1529 (1971).
[CrossRef]

MacRae, S.

S. MacRae, J. Schwiegerling, and R. W. Snyder, "Customized and low spherical aberration corneal ablation design," J. Refract. Surg. 15, S246-S248 (1999).
[PubMed]

Marcos, S.

S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
[CrossRef] [PubMed]

Martinez-Corral, M.

M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
[CrossRef]

Mrochen, M.

M. Mrochen, C. Donitzky, C. Wullner, and J. Loffler, "Wavefront-optimized ablation profiles: theoretical background," J. Cataract Refractive Surg. 30, 775-785 (2004).
[CrossRef]

Mutti, D. O.

D. O. Mutti, "Sources of normal and anomalous motion in retinoscopy," Opotom. Vision.Sci. 81, 663-672 (2004).
[CrossRef]

Navarro, R

Navarro, R.

R. Navarro, L. Gonzalez, and J. L. Hernandez-Matamoros, "On the prediction of optical aberrations by personalized eye models," Optom Vision Sci. 83, 371-381 (2006).
[CrossRef]

S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
[CrossRef] [PubMed]

I. Escudero-Sanz and R. Navarro, "Off-axis aberrations of a wide-angle schematic eye model," J. Opt. Soc. Am. A,  16, 1881-1891 (1999).
[CrossRef]

Pons, A.

M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
[CrossRef]

Preussner, P. R.

P. R. Preussner, J. Wahl, and D. Weitzel, "Topography-based intraocular lens power selection," J. Cataract Refractive Surg. 31, 525-33 (2005).
[CrossRef]

Prieto, P. M.

S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
[CrossRef] [PubMed]

Röhler, R.

R. Röhler and F. Schmeilau, "Properties of isolated frog retinae in reflecting non-polarized and polarized light," Vision Res. 16,241-246 (1976).
[CrossRef] [PubMed]

Roorda, A.

Saavedra, G.

M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
[CrossRef]

Santamaria, J.

Schmeilau, F.

R. Röhler and F. Schmeilau, "Properties of isolated frog retinae in reflecting non-polarized and polarized light," Vision Res. 16,241-246 (1976).
[CrossRef] [PubMed]

Schwiegerling, J.

S. MacRae, J. Schwiegerling, and R. W. Snyder, "Customized and low spherical aberration corneal ablation design," J. Refract. Surg. 15, S246-S248 (1999).
[PubMed]

Smith, G.

G. Smith and S. Haymes, "The streak retinoscopy pupil reflex in the presence of astigmatism," Ophthalmic Physiol. Opt. 23, 295-305 (2003).
[CrossRef]

Snyder, R. W.

S. MacRae, J. Schwiegerling, and R. W. Snyder, "Customized and low spherical aberration corneal ablation design," J. Refract. Surg. 15, S246-S248 (1999).
[PubMed]

Swaine, W.

W. Swaine, "Retinoscopy. I. General outline and symbols," Optician, April, 171-179 (1945).

W. Swaine, "Retinoscopy. II. Basic theoretical principles," Optician, June, 335-339 (1945).

W. Swaine, "Retinoscopy. III. Variation of illumination across the reflex," Optician, August, 35-40 (1945).

W. Swaine, "Retinoscopy. IV. Variation of the reflex brightness with refractive error and pupil diameter," Optician, August, 71-74 (1945).

Swartz, T.

Tan, B.

van Blokland, G. J.

G. J. van Blokland, "Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo," Vision Res. 26,495-500 (1986).
[CrossRef] [PubMed]

Wahl, J.

P. R. Preussner, J. Wahl, and D. Weitzel, "Topography-based intraocular lens power selection," J. Cataract Refractive Surg. 31, 525-33 (2005).
[CrossRef]

Wang, M.

Weitzel, D.

P. R. Preussner, J. Wahl, and D. Weitzel, "Topography-based intraocular lens power selection," J. Cataract Refractive Surg. 31, 525-33 (2005).
[CrossRef]

Wullner, C.

M. Mrochen, C. Donitzky, C. Wullner, and J. Loffler, "Wavefront-optimized ablation profiles: theoretical background," J. Cataract Refractive Surg. 30, 775-785 (2004).
[CrossRef]

Appl. Opt. (1)

J. Cataract Refractive Surg. (2)

M. Mrochen, C. Donitzky, C. Wullner, and J. Loffler, "Wavefront-optimized ablation profiles: theoretical background," J. Cataract Refractive Surg. 30, 775-785 (2004).
[CrossRef]

P. R. Preussner, J. Wahl, and D. Weitzel, "Topography-based intraocular lens power selection," J. Cataract Refractive Surg. 31, 525-33 (2005).
[CrossRef]

J. Opt. Soc. Am. (1)

W. Lotmar, "Theoretical eye model with aspherics," J. Opt. Soc. Am. 16, 1522-1529 (1971).
[CrossRef]

J. Opt. Soc. Am. A (4)

J. Refract. Surg. (1)

S. MacRae, J. Schwiegerling, and R. W. Snyder, "Customized and low spherical aberration corneal ablation design," J. Refract. Surg. 15, S246-S248 (1999).
[PubMed]

Ophthalmic Physiol. Opt. (1)

G. Smith and S. Haymes, "The streak retinoscopy pupil reflex in the presence of astigmatism," Ophthalmic Physiol. Opt. 23, 295-305 (2003).
[CrossRef]

Opt. Commun. (1)

M. T. Caballero, W. D. Furlan, A. Pons, G. Saavedra, and M. Martinez-Corral, "Detection of wave aberrations in the human eye using a retinoscopy-like technique," Opt. Commun. 260, 767-771 (2006).
[CrossRef]

Opt. Express (1)

Optician (4)

W. Swaine, "Retinoscopy. I. General outline and symbols," Optician, April, 171-179 (1945).

W. Swaine, "Retinoscopy. II. Basic theoretical principles," Optician, June, 335-339 (1945).

W. Swaine, "Retinoscopy. III. Variation of illumination across the reflex," Optician, August, 35-40 (1945).

W. Swaine, "Retinoscopy. IV. Variation of the reflex brightness with refractive error and pupil diameter," Optician, August, 71-74 (1945).

Optom Vision Sci. (1)

R. Navarro, L. Gonzalez, and J. L. Hernandez-Matamoros, "On the prediction of optical aberrations by personalized eye models," Optom Vision Sci. 83, 371-381 (2006).
[CrossRef]

Optom. Vision Sci. (1)

J. B. Almeida and A. M. Garcia, "Theoretical calculation of a contact lens thickness designed to correct the eye's monochromatic aberrations," Optom. Vision Sci. 82, 59-63 (2005).

Sci. (1)

D. O. Mutti, "Sources of normal and anomalous motion in retinoscopy," Opotom. Vision.Sci. 81, 663-672 (2004).
[CrossRef]

Vision Res. (5)

H. C. Howland, "Retinoscopy of infants at a distance: limits of normal and anomalous reflexes," Vision Res. 18, 597-599 (1978).
[CrossRef] [PubMed]

J.-M. Gorrand, A. Alfieri, and J.-Y. Boire, "Diffusion of the retinal layers of the living human eye," Vision Res. 24,1097-1106 (1984).
[CrossRef] [PubMed]

G. J. van Blokland, "Directionality and alignment of the foveal receptors, assessed with light scattered from the human fundus in vivo," Vision Res. 26,495-500 (1986).
[CrossRef] [PubMed]

R. Röhler and F. Schmeilau, "Properties of isolated frog retinae in reflecting non-polarized and polarized light," Vision Res. 16,241-246 (1976).
[CrossRef] [PubMed]

S. Marcos, S. A. Burns, P. M. Prieto, R. Navarro, and B. Baraibar, "Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes," Vision Res. 41, 3861-3871 (2001).
[CrossRef] [PubMed]

Other (7)

A. Gullstrand, "The Optical System of the Eye," in Physiological Optics, 3rd ed., H. von Helmholtz (Hamburg, Voss, 1909), Vols. 1 and 2, pp. 350-358.

H. Von Helmholtz, Physiological Optics, 3rd ed. (Hamburg, Voss, 1909), Vols. 1 and 2, pp. 91-121.

Y. Le Grand, Optique physiologique. T. 1. Dioptrique de l’oeil er sa correlations. English translation by S. G. el Hage. (Berlin, Springer-Verlag, 1980), pp. 64-67.

R. B. Bennett, Clinical Visual Optics, 3rd ed., (Butterworth-Heinemann, Oxford, 1998).

J. I. Pascal, Modern Retinoscopy (Hatton, London, 1930).

E. Landolt, "Methods of determination of the refraction and accommodation of the eye," in The Refraction and Accommodation of the Eye, C. M. Culver, ed. (Pentland, Edinburgh, 1886).

I. M. Borish, Clinical refraction, 3rd ed. (Professional press, Chicago, 1970).

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Figures (7)

Fig. 1.
Fig. 1.

Optical layout in the simulation of retinoscopic measurement. Wavelength of filament is set at 555 nm. The observation behind the peephole is simulated with a Gaussian lens that focuses on the cornea plane.

Fig. 2.
Fig. 2.

Simulation results of the retinoscopic observation as the condenser lens moves from a height of 10 mm (indicated as h=10 mm) to 25 mm above the filament. The left most column shows the streak projections on the surface of the examinee’s eye. The 5 columns on the right illustrate the appearances of retinal reflex of 5 eyes with +2, -1, -2, -4, and -6 diopter of refractive errors.

Fig. 3.
Fig. 3.

Streak retinoscopic reflex of an astigmatic eye, (S+1.00, C+2.00, X90). Both gray level and false color illustrations are scaled from 5% to 95% of the maximum intensity. The orientations of streak projections are indicated by dotted arrow lines.

Fig. 4.
Fig. 4.

Predicted retinal reflex motion of neutralization (top), with motion (middle), and against motion (bottom). Sleeve of retinoscope is located at 19 mm above the filament (plane-mirror).

Fig. 5.
Fig. 5.

Predicted retinal reflex motion of with motion and against motion under concave-mirror operation. Sleeve of retinoscope is located at 21 mm above the filament.

Fig. 6.
Fig. 6.

Anomalous retinal reflex of a myopic eye from a streak etinoscope.The top row shows the streak beam swiping from the left to the center of pupil. Sleeve position of retinoscope is 19 mm above the filament (plane mirror).

Fig. 7.
Fig. 7.

Simulated retinoscopic observation of a keratoconus eye. The upper images show the observation when the streak rotates along the pupillary axis. The lower images show the observation when streak swipes across the pupil in 135 degree angle. The scissors reflex that indicates the irregular cornea surface is clearly shown.

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