OBJECTIVE To evaluate factors associated with myopic shift among primary school children. METHODS In a one-year prospective school-based study, 5052 children from ten schools were enrolled using a multi-stage random cluster approach. The baseline examination included non-cycloplegic auto-refractometry and questionnaire interview. Measurements were repeated at the follow-up. RESULTS Among 50...

We present a novel method for in situ refractive index measurement of scattering samples using a needle device. The device employs a fiber-based reflectance refractometer and coherence-gated detection of the reflected optical signal that eliminates scattering-dependent backreflection contributions. Additionally, birefringence changes induced by fiber movement are neutralized by randomizing the ...

PREMISE OF THE STUDY Understanding floral resources is vital for restoring pollinators in habitats affected by anthropogenic development and climate change. As the primary adult food, nectar can limit butterfly longevity and reproduction. For pollinator restoration, it would therefore be useful to examine nectar resources. However, because many flowers preferred by butterflies are too small for...

PURPOSE To evaluate prevalence and associated factors for myopia in high school students in Beijing. METHODS Grade 10 and 11 high school students were randomly selected from nine randomly selected districts of Beijing. The students underwent non-cylcoplegic auto-refractometry and an interview. RESULTS Out of 4798 eligible students, 4677 (93.4%) students (mean age:16.9±0.7years;range:16-18 y...

A novel in-fiber structure for power-referenced refractometry with the capability to measure surrounding refractive index (SRI) as low as 1.33 is proposed and demonstrated. A short optical fiber stub containing a weakly tilted Bragg grating is spliced to another fiber with a large lateral offset. The reflection from this structure occurs in two well-defined wavelength bands, the Bragg reflected...

Parenteral nutrition (PN) solution contains various concentrations of dextrose, amino acids, lipids, vitamins, electrolytes, and trace elements. Incorrect preparation of PN solution could lead to patient death. In this study we used the refractive index as a quality assurance tool to monitor the preparation of PN solution. Refractive indices of single nutrient components and PN solutions consis...