Daytime, scotopic CS of Bovan chicks (n = 6–7) at minimal mean luminance (I_mean = −2.12).

<p>No unique tuning characteristic could be discerned at this luminance, as low-pass, bandpass, and high-pass characteristics were seen in the spatial CS functions (A), and both bandpass and low-pass characteristics were seen in the temporal CS functions (B).</p

Nighttime, scotopic CS function of Lohmann chicks at minimal mean luminance (I_mean = −1.62 log cd/m²).

<p>(A) At the two spatial frequencies to which chicks were most sensitive, CS was clearly tuned to TF, with maximum CS = 7.32±0.804 at about 1.8 cyc/sec (n = 8–10). (B) In contrast, over a wide range of temporal frequencies, CS was poorly tuned to SF, with no significant dependence upon SF at any TF (n = 7–10). (C) Contrast sensitivity function for quail pERG (purple line; Ref. 24) scaled and fitted by eye to CS function of Lohmann chicks (n = 8–10). Estimated temporal acuity is 10–20 Hz.</p

Daytime, photopic temporal CS functions.

<p>(A) Lohmann chicks (n = 6–8) and (B) Bovan chicks (n = 7–8), at unattenuated luminance (I_mean =1.98 log cd/m²); mean ± SD. The CS functions of Lohmann chicks showed no statistically significant preference for any temporal frequency (A). In Bovan chicks, at SF = 0.2 and 0.32 cyc/deg, CS appeared to be bandpass, whereas at SF = 0.1 and 0.5 cyc/deg, they appeared to be more high-pass (at SF = 0.5 cyc/deg, difference in CS between the three highest TFs was insignificant, one-way ANOVA). SF, spatial frequency.</p

Examples of daytime, photopic spatial CS functions.

<p>(A) Bovan chicks (n = 6–8), (B) Lohmann chicks (n = 8). Contrast sensitivity peaks at about 0.5 cyc/deg. (C) Contrast sensitivity function for quail pERG (purple line; Ref. 24) scaled and fitted by eye to CS function of Bovan chicks (n = 6–8). Unattenuated mean luminance (I_mean =1.98 log cd/m²) in all cases; mean ± SD. Peak CS is 13.2±2.8 in Bovan chicks (A, n = 8) and 19.1±5.2 in Lohmann chicks (B, n = 8), at ∼0.5 cyc/deg, and estimated SF_max (acuity) is ≥2 cyc/deg. TF, temporal frequency.</p

Contrast sensitivity functions under three conditions of adaptation and day-night cycle.

<p>(A) Temporal CS function at a specific SF (SF = 0.5 cyc/deg), under (i) daytime, photopic, (ii) daytime, threshold luminance, and (iii) nighttime, scotopic conditions. (B) Spatial CS functions at a specific TF (TF = 4.5 cyc/s), under the same three conditions as in (A).</p

Photopic OKR vs mean luminance: In light- adapted chicks, with contrast sensitivity adaptated to steady state at test luminance for 30–60 min, CS declined linearly with log₁₀ mean luminance (Weber’s Law).

<p>The critical threshold luminances, below which the photopic OKR was undetectable (in light-adapted chicks) and above which a scotopic OKR was elicited (in dark-adapted chicks), were statistically indistinguishable (P = 0.55) at −1.86 log₁₀ cd/m². Thus, rods and rod circuitry made no detectable contribution to even the scotopic OKR, under these daytime conditions.</p

Interocular differences in refraction and ocular parameters of infant monkeys in AL and NL.

<p>The interocular differences in spherical-equivalent refractive error (A-B), vitreous chamber depth (C-D) and corneal power (E-F) plotted as a function of time of lens wearing for individual infant monkeys reared under natural lighting (left panel) and artificial lighting (right panel) respectively.</p

Refractive errors of adolescent monkeys in the three groups.

<p>Spherical-equivalent refractive error measured at adolescence for the right (○) and left (●) eyes of individual monkeys from the three groups: (1) aged-matched normal group (Control), (2) NL group (Sunlight),(3) AL group (Artificial). The lines connect the right and left eyes of individual monkeys. The right eyes in the AL and NL group were treated with minus lenses early in life and the left eyes were contralateral eyes.</p

Relationship between anisometropia and interocular differences in vitreous chamber depth of adolescent monkeys in the three groups.

<p>Absolute interocular differences in spherical-equivalent refractive error plotted as a function of interocular differences in vitreous chamber depth for individual animals. Solid line: best-fitting regression line (y = -1.921x-0.091; r² = 0.769).</p

Primer sequences.

<p>Primer sequences.</p