title: [Measurement of ocular position using Purkinje images. Part 2. The measurement of ocular position in subjects wearing spectacles].
abstract: The first and the fourth Purkinje images are formed by the front surface of the cornea and the posterior surface of the lens. This measurement system is based on the principle of aligning one image with the other horizontally. It produces a precise measurement of the horizontal ocular position. I measured ocular position using this system when the subjects wore spectacles. The subjects gazed at a target position that was placed horizontally at 5 degrees intervals within a range of 25 degrees from the center to both sides. I analyzed the differences between the target position and the measurement data obtained by this system. The higher the refractive power of the lens the subjects wore, and the further the target position was from the center the greater were the differences between them. If the fixed target was placed within +/- 10 degrees, the difference was less than 0.5 degrees in all the spectacle lenses tested. I concluded that the measurements obtained with this system were useful even when the subjects wore spectacles.
authors.affiliation: Department of Ophthalmology, Okayama University Medical School, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Watanabe
mesh_terms: D000293:Adolescent; D000328:Adult; D005133:Eye Movements / Q000502:physiology*; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male