Traditional color vision tests lack the sensitivity to detect subtle differences in individuals with normal color vision. The Konan ColorDx Cone Contrast Threshold (CCT) HD test allows the quantitative measurement of color discrimination thresholds for each cone type. This cross-sectional study established normative values for L-, M-, and S-cone contrast sensitivities and evaluated the effects of age and sex on color discrimination thresholds. Participants aged 15–79 years with normal color vision were included (n = 216; 55% female). CCTs were measured monocularly using the Konan ColorDx CCT HD test under standardized conditions, and the influences of age and sex on L-, M-, and S-cone sensitivities were evaluated. In all groups, L-cone sensitivity was the highest, followed by the M- and S-cone sensitivities. Overall contrast sensitivity was significantly higher in females than in males (mean difference = −0.041), especially for adolescents and young adults (20–24 years). Young adults outperformed middle-aged and older adults, with age-related decline most pronounced for S-cone sensitivity in those over 60. The right and left eye sensitivities did not differ. This study provides age- and sex-stratified normative data for the Konan Color Dx CCT HD test, supporting its use for clinical and occupational assessments.

This study aimed to evaluate the static and dynamic pupil changes, and light sensitivity following a single dose of low-dose atropine at concentrations of 0.01%, 0.025%, and 0.05% over a 24 h period. Healthy young adults (20–22 years; n = 25) participated in this randomized, double-blind study. Each participant received one of three atropine concentrations in a masked fashion. Baseline mesopic and dynamic pupil sizes were measured at various post-instillation intervals (5 min, 30 min, 1 h, 2 h, 4 h, and 24 h). A minimum 48 h washout period was observed between treatments. Subjective light sensitivity was assessed using the Visual Light Sensitivity Questionnaire (VLSQ-8) at 24 h. All atropine concentrations caused significant pupil dilation (p < 0.001), with the 0.05% concentration producing the greatest dilation (peak mesopic size: 7.4 mm, p < 0.001) and the slowest recovery at 24 h (6.4 mm, p < 0.001). The dynamic pupil constriction range was most restricted with 0.05% (1.7 mm, p < 0.05), compared to 0.025% (2.2 mm) and 0.01% (2.6 mm). Subjective symptoms, including light sensitivity and glare, followed a dose-dependent pattern (p < 0.05). In 60% participants, 0.05% caused the most symptoms, while in 70% participants, 0.01% caused the least. Despite significant pupil dilation, the pupil center coordinates did not shift significantly along the horizontal or vertical axes (p > 0.05). Low-dose atropine induced dose-dependent pupil dilation and light sensitivity; 0.05% atropine caused the most pronounced effects. These findings underscore the importance of tailoring the atropine dosage to balance its efficacy and tolerability. Further studies are needed to explore the long-term impact of repeated dosing on pupillary behavior and subjective symptoms.

Background: Measuring contrast sensitivity for each of the three cone types separately allows for a more precise and clinically valuable assessment of color vision. This study examined how pupil size affects cone contrast sensitivity (CCS). Methods: This study included 50 participants of equal gender. The mean age was 20.88 (±1.8) years. Using the ColorDx, a Landolt C stimulus of various sizes in an adaptive screening mode, we sequentially determined contrast sensitivity for long-, medium-, and short-wavelength stimuli. Two consecutive measurements were performed on participants, one with their natural pupil size (range 4–5 mm diameter) and, subsequently, with six artificial eye pupils (1 mm to 6 mm). Results: Generally, the 1 mm pupil size caused the greatest reduction in contrast sensitivity for two of the three cones. There was no significant main effect of sex (F = 0.96, df = 1, p = 0.32) on the log cone contrast sensitivity of the L-cone. However, pupil size had a significant main effect (F = 116.1, df = 6, p < 0.001). Within each sex, the log CCS was significantly reduced as the pupil size decreased compared with the normal pupil size. Conclusions: New technologies that assess individual cone pathway functions could potentially assist in identifying early or progressive conditions that may impact color vision pathways from the retina to the brain. Standardized protocols—such as controlled retinal illumination—are critical to avoid misinterpretation.

Omega-3 fatty acids can reduce inflammation and, as a result, decrease the production of inflammatory mediators. The study aimed to evaluate the short-term effects of omega-3 fatty acid supplementation on the tear film. Fifty subjects aged 18 to 27 years were recruited. All subjects received 2 soft gels of molecularly distilled omega-3 fatty acids for 3 consecutive days. A control age-matched group of 50 subjects was included for comparison. The standard patient evaluation of eye dryness (SPEED) questionnaire was completed, followed by the noninvasive tear breakup time (NITBUT), tear meniscus height (TMH), and tear ferning (TF) tests. The first measurements were taken before the supplement was consumed, and the second measurements were taken 24 hours after the third dose of omega-3 fatty acids was administered. The control group subjects did not get omega-3, with measurements on days 1 and 4. Significant (Wilcoxon signed-rank test) differences were found in the median scores of the SPEED ( P <.001), NITBUT ( P <.001), and TF ( P = .040) before and after the consumption of omega-3 fatty acids. However, consuming omega-3 fatty acids showed no significant difference in TMH score. For the control group, no significant differences were observed in the SPEED ( P = .093), NITBUT ( P = .149), TMH ( P = .831), and TF ( P = .567) scores between days 1 and 4. The oral consumption of omega-3 fatty acids over 3 consecutive days significantly improved the comfort, stability, and quality of the ocular tear film. However, no significant change was observed in tear volume after the consumption of omega-3 fatty acids. Further research is still necessary to verify the general applicability of the findings and to address the existing limitations.

Background: Individuals with congenital color vision defects (CVDs) are at greater risk of misidentifying colors, necessitating an investigation into their ability to distinguish colors accurately. This study aimed to assess how individuals with CVDs perceive the colors in the Worth four-dot (W4D) and duochrome tests. It also explored whether individuals with CVDs require more detailed instructions from optometrists and eye care providers during these tests. Method: Thirty-two participants with congenital CVDs were recruited for this study. Participants with ocular diseases were excluded based on a brief questionnaire. The participants underwent a W4D test to determine the colors of four circles and the duochrome test without using filters. Result: All the participants correctly identified the W4D colors, except for five participants (15.62%). Furthermore, among all the participants, two (one with deuteranopia and one with protanopia) failed to identify the colors correctly in the duochrome test (6.25%). Conclusions: The findings suggest that in the context of optometric assessment, it could be essential for optometrists to incorporate a preliminary inquiry into a patient’s ability to identify colors prior to performing diagnostic tests such as the W4D or duochrome tests. Incorrect responses from patients with CVDs might mislead optometrists regarding the proper outcomes of the test.