Retinal-image quality and night-vision performance after alcohol consumption.

Purpose. To evaluate the influence of alcohol consumption on the retinal-image quality and visual performance under surrounding low-illumination conditions. Methods.

Theoretical analysis of the effect of pupil size, initial myopic level, and optical zone on quality of vision after corneal refractive surgery.

Purpose: To analyze the theoretical effect that pupil size, optical zone, and initial myopic level have on the final retinal image after corneal refractive surgery.

Methods: A schematic myopic eye model corrected by the Munnerlyn formula was used to analyze the optical quality of the final retinal image. Root-mean-square radius spot and modulation transfer function were cal- culated by ray tracing to evaluate retinal image quality.

Optical characterization of ophthalmic lenses by means of modulation transfer function determination from a laser speckle pattern.

A method is presented for measuring the modulation transfer function of ophthalmic lenses by use of the generation of laser speckle with an integrating sphere. The measurements are performed with a rectangular double-slit aperture positioned at the output port of the integrating sphere. The distance between the lens and the detector determines the spatial frequency being tested; therefore high frequencies are tested close to the lens and low frequencies are tested far away from the lens.

Comparative analysis of techniques for measuring the modulation transfer functions of charge-coupled devices based on the generation of laser speckle.

Two methods for measuring the modulation transfer function (MTF) of a charge-coupled device (CCD) that are based on the generation of laser speckle are analyzed and compared. The method based on a single-slit aperture is a quick method, although the measurements are limited to values of less than the Nyquist frequency of the device. The double-slit method permits the measurement of values of as much as some 1.

Prevalence of myopia in an adult population of two different ethnic groups in the Ecuadorian Amazon.

Purpose: To determine the prevalence of myopia in the adult populations of two different ethnic communities in the Ecuadorian Amazon.

Methods: Refraction with retinoscopy after cycloplegia was performed for 507 Naporuna (an ethnic group indigenous to the jungles of the Ecuadorian Amazon) and for 776 settlers (white-mestizos from the Andes, now living in the Amazon and working for the petroleum industry). Ages ranged from 18 to 45 years.

Objective measurement of dental color for age estimation by spectroradiometry.

Age-related changes in tooth color have been described previously, however, the use of dental color for age estimation in forensic odontology has been limited due to the difficulty of measuring color objectively. This study presents an objective method for determining dental color to estimate the age of an individual. Dentine color in 250 teeth from patients ranging in age from 10 to 89 years was determined by spectroradiometry.