Abstract

Flicker thresholds were measured in an automated paradigm at several temporal frequencies for the critical fusion frequency in more than 1000 observers of ages 5–75 years. The results can be described by two processes. The first process was a uniform increase in sensitivity at all frequencies, at a rate that would double sensitivity every 10 years, up to the age of 16 years. In the second process the data indicated that after the age of 16 years the visual response showed gradual slowing but little sensitivity decrease for the remainder of the life span.

© 1989 Optical Society of America

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References

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  1. C. W. Tyler, “Specific deficits of flicker sensitivity in glaucoma and ocular hypertension,” Invest. Ophthalmol. Vis. Sci. 20, 204–212 (1981).
    [PubMed]
  2. R. L. Stamper, C. W. Tyler, “Effect of glaucoma on central visual function,” in Recent Advances in Glaucoma, U. Ticho, R. David, eds. (Elsevier, Amsterdam, 1984).
  3. J. R. Buncic, M. E. Tytla, G. E. Trope, “Flicker sensitivity in ocular hypertension before and during hypotensive treatment,” Invest. Ophthalmol. Vis. Sci. Suppl. 27, 158 (1986).
  4. C. W. Tyler, W. J. K. Ernst, A. L. Lyness, “Photopic flicker sensitivity losses in simplex and multiplex retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 25, 1035–1042 (1986).
  5. E. Wolf, A. M. Gaeta, S. E. Geer, “Critical flicker frequencies in flicker perimetry,” Arch. Ophthalmol. 80, 347–351 (1968).
    [Crossref] [PubMed]
  6. C. E. Wright, N. Drasdo, “The influence of age on the spatial and temporal contrast sensitivity function,” Doc. Ophthalmol. 59, 385–395 (1985).
    [Crossref] [PubMed]
  7. D. V. Van Norren, J. J. Vos, “Spectral transmission of the human ocular media,” Vision Res. 14, 1237–1244 (1974).
    [Crossref]
  8. J. S. Werner, “Development of scotopic spectral sensitivity and the absorption spectrum of the human ocular media,”J. Opt. Soc. Am. 72, 247–258 (1982).
    [Crossref] [PubMed]
  9. V. C. Smith, J. Pokorny, “Spectral sensitivity of color-blind observers and the cone photopigments,” Vision Res. 12, 2059–2071 (1972).
    [Crossref] [PubMed]
  10. J. L. Schnapf, T. W. Kraft, D. A. Baylor, “Spectral sensitivity of human cone photoreceptors,” Nature 325, 439–441 (1987).
    [Crossref] [PubMed]
  11. J. W. Tukey, D. H. McLaughlin, “Less vulnerable confidence and significance procedures for location based on a single sample: trimming/Winsorization,” Sankhya Ser. A 25, 331–352 (1963).
  12. A. Gorea, C. W. Tyler, “New look at Bloch’s law for contrast,” J. Opt. Soc. Am. A 3, 52–61 (1986).
    [Crossref] [PubMed]
  13. C. W. Tyler, “Analysis of visual modulation sensitivity. II. Peripheral sensitivity and the role of photoreceptor dimensions,” J. Opt. Soc. Am. A 2, 393–398 (1985).
    [Crossref] [PubMed]
  14. D. A. Baylor, T. D. Lamb, K. W. Yau, “The membrane current of single rod outer segments,”J. Physiol. 28, 589–611 (1979).
  15. A. E. Hendricksen, C. Yuodelis, “The morphological development of the human fovea,” Ophthalmologica 91, 603–612 (1984).
  16. S. Polyak, The Retina (U. Chicago Press, Chicago, Ill., 1941).
  17. L. H. DeVries-Khoe, H. Spekreijse, “Maturation of luminance and pattern EPs in man,” Doc. Ophthalmol. Proc. Ser. 31, 461–475 (1982).
  18. H. Spekreijse, “Comparison of acuity tests and pattern evoked potential criteria: two mechanisms underlying acuity maturation in man,” Behav. Brain Res. 10, 107–117 (1983).
    [Crossref] [PubMed]
  19. C. Owsley, R. Sekuler, D. Siemsen, “Contrast sensitivity throughout adulthood,” Vision Res. 23, 689–699 (1983).
    [Crossref] [PubMed]
  20. A. B. Watson, “Derivation of the impulse response: comments on the method of Roufs and Blommeart,” Vision Res. 22, 1335–1337 (1982).
    [Crossref]
  21. P. A. Sample, F. D. Esterson, R. N. Weinreb, R. M. Boynton, “The aging lens: in vivo assessment of light absorption in 84 human eyes,” Invest. Ophthalmol. Vis. Sci. 29, 1306–1311 (1988).
    [PubMed]
  22. H. de Lange, “Research in the dynamic nature of the human fovea-cortex systems with intermittent and modulated light. I. Attenuation characteristics with white and colored light,”J. Opt. Soc. Am. 48, 777–784 (1958).
    [Crossref]
  23. D. H. Kelly, “Visual responses to time-dependent stimuli. I. Amplitude sensitivity measurements,”J. Opt. Soc. Am. 51, 422–429 (1961).
    [Crossref]
  24. D. M. Regal, “Development of critical flicker frequency in human infants,” Vision Res. 21, 549–561 (1981).
    [Crossref] [PubMed]

1988 (1)

P. A. Sample, F. D. Esterson, R. N. Weinreb, R. M. Boynton, “The aging lens: in vivo assessment of light absorption in 84 human eyes,” Invest. Ophthalmol. Vis. Sci. 29, 1306–1311 (1988).
[PubMed]

1987 (1)

J. L. Schnapf, T. W. Kraft, D. A. Baylor, “Spectral sensitivity of human cone photoreceptors,” Nature 325, 439–441 (1987).
[Crossref] [PubMed]

1986 (3)

J. R. Buncic, M. E. Tytla, G. E. Trope, “Flicker sensitivity in ocular hypertension before and during hypotensive treatment,” Invest. Ophthalmol. Vis. Sci. Suppl. 27, 158 (1986).

C. W. Tyler, W. J. K. Ernst, A. L. Lyness, “Photopic flicker sensitivity losses in simplex and multiplex retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 25, 1035–1042 (1986).

A. Gorea, C. W. Tyler, “New look at Bloch’s law for contrast,” J. Opt. Soc. Am. A 3, 52–61 (1986).
[Crossref] [PubMed]

1985 (2)

C. E. Wright, N. Drasdo, “The influence of age on the spatial and temporal contrast sensitivity function,” Doc. Ophthalmol. 59, 385–395 (1985).
[Crossref] [PubMed]

C. W. Tyler, “Analysis of visual modulation sensitivity. II. Peripheral sensitivity and the role of photoreceptor dimensions,” J. Opt. Soc. Am. A 2, 393–398 (1985).
[Crossref] [PubMed]

1984 (1)

A. E. Hendricksen, C. Yuodelis, “The morphological development of the human fovea,” Ophthalmologica 91, 603–612 (1984).

1983 (2)

H. Spekreijse, “Comparison of acuity tests and pattern evoked potential criteria: two mechanisms underlying acuity maturation in man,” Behav. Brain Res. 10, 107–117 (1983).
[Crossref] [PubMed]

C. Owsley, R. Sekuler, D. Siemsen, “Contrast sensitivity throughout adulthood,” Vision Res. 23, 689–699 (1983).
[Crossref] [PubMed]

1982 (3)

A. B. Watson, “Derivation of the impulse response: comments on the method of Roufs and Blommeart,” Vision Res. 22, 1335–1337 (1982).
[Crossref]

L. H. DeVries-Khoe, H. Spekreijse, “Maturation of luminance and pattern EPs in man,” Doc. Ophthalmol. Proc. Ser. 31, 461–475 (1982).

J. S. Werner, “Development of scotopic spectral sensitivity and the absorption spectrum of the human ocular media,”J. Opt. Soc. Am. 72, 247–258 (1982).
[Crossref] [PubMed]

1981 (2)

C. W. Tyler, “Specific deficits of flicker sensitivity in glaucoma and ocular hypertension,” Invest. Ophthalmol. Vis. Sci. 20, 204–212 (1981).
[PubMed]

D. M. Regal, “Development of critical flicker frequency in human infants,” Vision Res. 21, 549–561 (1981).
[Crossref] [PubMed]

1979 (1)

D. A. Baylor, T. D. Lamb, K. W. Yau, “The membrane current of single rod outer segments,”J. Physiol. 28, 589–611 (1979).

1974 (1)

D. V. Van Norren, J. J. Vos, “Spectral transmission of the human ocular media,” Vision Res. 14, 1237–1244 (1974).
[Crossref]

1972 (1)

V. C. Smith, J. Pokorny, “Spectral sensitivity of color-blind observers and the cone photopigments,” Vision Res. 12, 2059–2071 (1972).
[Crossref] [PubMed]

1968 (1)

E. Wolf, A. M. Gaeta, S. E. Geer, “Critical flicker frequencies in flicker perimetry,” Arch. Ophthalmol. 80, 347–351 (1968).
[Crossref] [PubMed]

1963 (1)

J. W. Tukey, D. H. McLaughlin, “Less vulnerable confidence and significance procedures for location based on a single sample: trimming/Winsorization,” Sankhya Ser. A 25, 331–352 (1963).

1961 (1)

1958 (1)

Baylor, D. A.

J. L. Schnapf, T. W. Kraft, D. A. Baylor, “Spectral sensitivity of human cone photoreceptors,” Nature 325, 439–441 (1987).
[Crossref] [PubMed]

D. A. Baylor, T. D. Lamb, K. W. Yau, “The membrane current of single rod outer segments,”J. Physiol. 28, 589–611 (1979).

Boynton, R. M.

P. A. Sample, F. D. Esterson, R. N. Weinreb, R. M. Boynton, “The aging lens: in vivo assessment of light absorption in 84 human eyes,” Invest. Ophthalmol. Vis. Sci. 29, 1306–1311 (1988).
[PubMed]

Buncic, J. R.

J. R. Buncic, M. E. Tytla, G. E. Trope, “Flicker sensitivity in ocular hypertension before and during hypotensive treatment,” Invest. Ophthalmol. Vis. Sci. Suppl. 27, 158 (1986).

de Lange, H.

DeVries-Khoe, L. H.

L. H. DeVries-Khoe, H. Spekreijse, “Maturation of luminance and pattern EPs in man,” Doc. Ophthalmol. Proc. Ser. 31, 461–475 (1982).

Drasdo, N.

C. E. Wright, N. Drasdo, “The influence of age on the spatial and temporal contrast sensitivity function,” Doc. Ophthalmol. 59, 385–395 (1985).
[Crossref] [PubMed]

Ernst, W. J. K.

C. W. Tyler, W. J. K. Ernst, A. L. Lyness, “Photopic flicker sensitivity losses in simplex and multiplex retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 25, 1035–1042 (1986).

Esterson, F. D.

P. A. Sample, F. D. Esterson, R. N. Weinreb, R. M. Boynton, “The aging lens: in vivo assessment of light absorption in 84 human eyes,” Invest. Ophthalmol. Vis. Sci. 29, 1306–1311 (1988).
[PubMed]

Gaeta, A. M.

E. Wolf, A. M. Gaeta, S. E. Geer, “Critical flicker frequencies in flicker perimetry,” Arch. Ophthalmol. 80, 347–351 (1968).
[Crossref] [PubMed]

Geer, S. E.

E. Wolf, A. M. Gaeta, S. E. Geer, “Critical flicker frequencies in flicker perimetry,” Arch. Ophthalmol. 80, 347–351 (1968).
[Crossref] [PubMed]

Gorea, A.

Hendricksen, A. E.

A. E. Hendricksen, C. Yuodelis, “The morphological development of the human fovea,” Ophthalmologica 91, 603–612 (1984).

Kelly, D. H.

Kraft, T. W.

J. L. Schnapf, T. W. Kraft, D. A. Baylor, “Spectral sensitivity of human cone photoreceptors,” Nature 325, 439–441 (1987).
[Crossref] [PubMed]

Lamb, T. D.

D. A. Baylor, T. D. Lamb, K. W. Yau, “The membrane current of single rod outer segments,”J. Physiol. 28, 589–611 (1979).

Lyness, A. L.

C. W. Tyler, W. J. K. Ernst, A. L. Lyness, “Photopic flicker sensitivity losses in simplex and multiplex retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 25, 1035–1042 (1986).

McLaughlin, D. H.

J. W. Tukey, D. H. McLaughlin, “Less vulnerable confidence and significance procedures for location based on a single sample: trimming/Winsorization,” Sankhya Ser. A 25, 331–352 (1963).

Owsley, C.

C. Owsley, R. Sekuler, D. Siemsen, “Contrast sensitivity throughout adulthood,” Vision Res. 23, 689–699 (1983).
[Crossref] [PubMed]

Pokorny, J.

V. C. Smith, J. Pokorny, “Spectral sensitivity of color-blind observers and the cone photopigments,” Vision Res. 12, 2059–2071 (1972).
[Crossref] [PubMed]

Polyak, S.

S. Polyak, The Retina (U. Chicago Press, Chicago, Ill., 1941).

Regal, D. M.

D. M. Regal, “Development of critical flicker frequency in human infants,” Vision Res. 21, 549–561 (1981).
[Crossref] [PubMed]

Sample, P. A.

P. A. Sample, F. D. Esterson, R. N. Weinreb, R. M. Boynton, “The aging lens: in vivo assessment of light absorption in 84 human eyes,” Invest. Ophthalmol. Vis. Sci. 29, 1306–1311 (1988).
[PubMed]

Schnapf, J. L.

J. L. Schnapf, T. W. Kraft, D. A. Baylor, “Spectral sensitivity of human cone photoreceptors,” Nature 325, 439–441 (1987).
[Crossref] [PubMed]

Sekuler, R.

C. Owsley, R. Sekuler, D. Siemsen, “Contrast sensitivity throughout adulthood,” Vision Res. 23, 689–699 (1983).
[Crossref] [PubMed]

Siemsen, D.

C. Owsley, R. Sekuler, D. Siemsen, “Contrast sensitivity throughout adulthood,” Vision Res. 23, 689–699 (1983).
[Crossref] [PubMed]

Smith, V. C.

V. C. Smith, J. Pokorny, “Spectral sensitivity of color-blind observers and the cone photopigments,” Vision Res. 12, 2059–2071 (1972).
[Crossref] [PubMed]

Spekreijse, H.

H. Spekreijse, “Comparison of acuity tests and pattern evoked potential criteria: two mechanisms underlying acuity maturation in man,” Behav. Brain Res. 10, 107–117 (1983).
[Crossref] [PubMed]

L. H. DeVries-Khoe, H. Spekreijse, “Maturation of luminance and pattern EPs in man,” Doc. Ophthalmol. Proc. Ser. 31, 461–475 (1982).

Stamper, R. L.

R. L. Stamper, C. W. Tyler, “Effect of glaucoma on central visual function,” in Recent Advances in Glaucoma, U. Ticho, R. David, eds. (Elsevier, Amsterdam, 1984).

Trope, G. E.

J. R. Buncic, M. E. Tytla, G. E. Trope, “Flicker sensitivity in ocular hypertension before and during hypotensive treatment,” Invest. Ophthalmol. Vis. Sci. Suppl. 27, 158 (1986).

Tukey, J. W.

J. W. Tukey, D. H. McLaughlin, “Less vulnerable confidence and significance procedures for location based on a single sample: trimming/Winsorization,” Sankhya Ser. A 25, 331–352 (1963).

Tyler, C. W.

A. Gorea, C. W. Tyler, “New look at Bloch’s law for contrast,” J. Opt. Soc. Am. A 3, 52–61 (1986).
[Crossref] [PubMed]

C. W. Tyler, W. J. K. Ernst, A. L. Lyness, “Photopic flicker sensitivity losses in simplex and multiplex retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 25, 1035–1042 (1986).

C. W. Tyler, “Analysis of visual modulation sensitivity. II. Peripheral sensitivity and the role of photoreceptor dimensions,” J. Opt. Soc. Am. A 2, 393–398 (1985).
[Crossref] [PubMed]

C. W. Tyler, “Specific deficits of flicker sensitivity in glaucoma and ocular hypertension,” Invest. Ophthalmol. Vis. Sci. 20, 204–212 (1981).
[PubMed]

R. L. Stamper, C. W. Tyler, “Effect of glaucoma on central visual function,” in Recent Advances in Glaucoma, U. Ticho, R. David, eds. (Elsevier, Amsterdam, 1984).

Tytla, M. E.

J. R. Buncic, M. E. Tytla, G. E. Trope, “Flicker sensitivity in ocular hypertension before and during hypotensive treatment,” Invest. Ophthalmol. Vis. Sci. Suppl. 27, 158 (1986).

Van Norren, D. V.

D. V. Van Norren, J. J. Vos, “Spectral transmission of the human ocular media,” Vision Res. 14, 1237–1244 (1974).
[Crossref]

Vos, J. J.

D. V. Van Norren, J. J. Vos, “Spectral transmission of the human ocular media,” Vision Res. 14, 1237–1244 (1974).
[Crossref]

Watson, A. B.

A. B. Watson, “Derivation of the impulse response: comments on the method of Roufs and Blommeart,” Vision Res. 22, 1335–1337 (1982).
[Crossref]

Weinreb, R. N.

P. A. Sample, F. D. Esterson, R. N. Weinreb, R. M. Boynton, “The aging lens: in vivo assessment of light absorption in 84 human eyes,” Invest. Ophthalmol. Vis. Sci. 29, 1306–1311 (1988).
[PubMed]

Werner, J. S.

Wolf, E.

E. Wolf, A. M. Gaeta, S. E. Geer, “Critical flicker frequencies in flicker perimetry,” Arch. Ophthalmol. 80, 347–351 (1968).
[Crossref] [PubMed]

Wright, C. E.

C. E. Wright, N. Drasdo, “The influence of age on the spatial and temporal contrast sensitivity function,” Doc. Ophthalmol. 59, 385–395 (1985).
[Crossref] [PubMed]

Yau, K. W.

D. A. Baylor, T. D. Lamb, K. W. Yau, “The membrane current of single rod outer segments,”J. Physiol. 28, 589–611 (1979).

Yuodelis, C.

A. E. Hendricksen, C. Yuodelis, “The morphological development of the human fovea,” Ophthalmologica 91, 603–612 (1984).

Arch. Ophthalmol. (1)

E. Wolf, A. M. Gaeta, S. E. Geer, “Critical flicker frequencies in flicker perimetry,” Arch. Ophthalmol. 80, 347–351 (1968).
[Crossref] [PubMed]

Behav. Brain Res. (1)

H. Spekreijse, “Comparison of acuity tests and pattern evoked potential criteria: two mechanisms underlying acuity maturation in man,” Behav. Brain Res. 10, 107–117 (1983).
[Crossref] [PubMed]

Doc. Ophthalmol. (1)

C. E. Wright, N. Drasdo, “The influence of age on the spatial and temporal contrast sensitivity function,” Doc. Ophthalmol. 59, 385–395 (1985).
[Crossref] [PubMed]

Doc. Ophthalmol. Proc. Ser. (1)

L. H. DeVries-Khoe, H. Spekreijse, “Maturation of luminance and pattern EPs in man,” Doc. Ophthalmol. Proc. Ser. 31, 461–475 (1982).

Invest. Ophthalmol. Vis. Sci. (3)

P. A. Sample, F. D. Esterson, R. N. Weinreb, R. M. Boynton, “The aging lens: in vivo assessment of light absorption in 84 human eyes,” Invest. Ophthalmol. Vis. Sci. 29, 1306–1311 (1988).
[PubMed]

C. W. Tyler, “Specific deficits of flicker sensitivity in glaucoma and ocular hypertension,” Invest. Ophthalmol. Vis. Sci. 20, 204–212 (1981).
[PubMed]

C. W. Tyler, W. J. K. Ernst, A. L. Lyness, “Photopic flicker sensitivity losses in simplex and multiplex retinitis pigmentosa,” Invest. Ophthalmol. Vis. Sci. 25, 1035–1042 (1986).

Invest. Ophthalmol. Vis. Sci. Suppl. (1)

J. R. Buncic, M. E. Tytla, G. E. Trope, “Flicker sensitivity in ocular hypertension before and during hypotensive treatment,” Invest. Ophthalmol. Vis. Sci. Suppl. 27, 158 (1986).

J. Opt. Soc. Am. (3)

J. Opt. Soc. Am. A (2)

J. Physiol. (1)

D. A. Baylor, T. D. Lamb, K. W. Yau, “The membrane current of single rod outer segments,”J. Physiol. 28, 589–611 (1979).

Nature (1)

J. L. Schnapf, T. W. Kraft, D. A. Baylor, “Spectral sensitivity of human cone photoreceptors,” Nature 325, 439–441 (1987).
[Crossref] [PubMed]

Ophthalmologica (1)

A. E. Hendricksen, C. Yuodelis, “The morphological development of the human fovea,” Ophthalmologica 91, 603–612 (1984).

Sankhya Ser. A (1)

J. W. Tukey, D. H. McLaughlin, “Less vulnerable confidence and significance procedures for location based on a single sample: trimming/Winsorization,” Sankhya Ser. A 25, 331–352 (1963).

Vision Res. (5)

C. Owsley, R. Sekuler, D. Siemsen, “Contrast sensitivity throughout adulthood,” Vision Res. 23, 689–699 (1983).
[Crossref] [PubMed]

A. B. Watson, “Derivation of the impulse response: comments on the method of Roufs and Blommeart,” Vision Res. 22, 1335–1337 (1982).
[Crossref]

V. C. Smith, J. Pokorny, “Spectral sensitivity of color-blind observers and the cone photopigments,” Vision Res. 12, 2059–2071 (1972).
[Crossref] [PubMed]

D. V. Van Norren, J. J. Vos, “Spectral transmission of the human ocular media,” Vision Res. 14, 1237–1244 (1974).
[Crossref]

D. M. Regal, “Development of critical flicker frequency in human infants,” Vision Res. 21, 549–561 (1981).
[Crossref] [PubMed]

Other (2)

R. L. Stamper, C. W. Tyler, “Effect of glaucoma on central visual function,” in Recent Advances in Glaucoma, U. Ticho, R. David, eds. (Elsevier, Amsterdam, 1984).

S. Polyak, The Retina (U. Chicago Press, Chicago, Ill., 1941).

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Figures (5)

Fig. 1
Fig. 1

Distributions of individual responses under each frequency condition before (open columns) and after (filled columns) the data were screened and Winsorized for unreliable responses. The distributions show that the cleaning procedures had little effect on the bulk of the distributions and acted mainly to eliminate the sparse tail of poor responses.

Fig. 2
Fig. 2

Standard deviations of flicker sensitivity as a function of age under four frequency conditions: (a), (b), (c), standard deviations for sensitivities to sinusoidal modulation at 5, 20, and 36 Hz, respectively; (d), standard deviation of the CFF for 100% sinusoidal modulation. Note the minimal effect of age under all conditions.

Fig. 3
Fig. 3

Flicker sensitivities as a function of age (2-year bins) under four frequency conditions: (a), (b), (c) sensitivities to sinusoidal modulation at 5, 20, and 36 Hz, respectively; (d) CFF for 100% sinusoidal modulation. Note the increase in sensitivity throughout adolescence at all frequencies and the stabilization or small decline through adulthood at higher modulation frequencies. Straight lines represent best-fitting exponential growth and decline functions as described in the text.

Fig. 4
Fig. 4

Flicker sensitivities as a function of age up to 70 years (10-year bins is) at 5, 20, and 36 Hz and effective sensitivity for the CFF data (see text). Note the stability of sensitivity at low temporal frequencies and the reduction in sensitivity with age as the test frequency is increased. Straight lines are best-fitting declining exponential functions described in the text.

Fig. 5
Fig. 5

(Top) Flicker sensitivities replotted as a function of temporal frequency for age ranges of 5–6, 15–16, and 66–75 years to illustrate the changes in temporal-frequency tuning with age. Curves are best-fitting derivatives of nine-pole filter functions. (Bottom) Impulse-response curves for the best-fitting filter functions above. These curves illustrate the effects of the two processes of age variation on the temporal response of visual sensitivity.

Tables (7)

Tables Icon

Table 1 Numbers of Observers per Age Group for the Fine-Grain Analysisa

Tables Icon

Table 2 Standard Deviations of Results across the Entire Population

Tables Icon

Table 3 Transition Ages for Best Fits of Two-Phase Process

Tables Icon

Table 4 Statistical Slope Analysis for the Fine-Grain Dataa

Tables Icon

Table 5 Numbers in Each Age Group for 10-Year Increments

Tables Icon

Table 6 Slope Analysis for the 10-Year Increment Dataa

Tables Icon

Table 7 Pupil Diameter as a Function of Age

Equations (1)

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h ( t ) = t 7 e - t / τ - 1 8 τ t 8 e - t / τ ,

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