title: Preliminary observations concerning treatment of visual discomfort and associated perceptual distortion.
abstract: A system for therapeutic precision tinting is described. Some individuals who are subject to perceptual distortion of text no longer perceive the distortion when the text has a particular colour. A simple colorimeter enables an observer to illuminate text with light of a particular chromaticity, varying first CIE 1976 hue angle (huv), then saturation (suv), and then luminance, to obtain a setting that maximizes visual comfort and reduces any perceptual distortion. The colorimeter setting is then matched by a combination of tinted trial lenses. The combination uses only two dyes at a time from a selection of seven, unless a dark lens is required, when a third neutral (grey) dye is added. The subject observes both text and a normal scene when wearing tinted trial lenses. A variety of trial lenses are compared including those that match the colorimeter setting and others with similar hue angle. Spectacle lenses are then tinted so as to have a spectral transmission identical to that of the chosen combination of trial lenses. Certain patients with reading disorders, eye-strain, headaches or photosensitivity epilepsy report benefit when wearing spectacles tinted according to the above techniques. The physiological basis for the therapeutic effects is uncertain, but may involve a selective impairment of luminance or colour-difference channels.
authors.affiliation: MRC Applied Psychology Unit, Cambridge, UK.
authors.forename: A
authors.initials: A
authors.lastname: Wilkins
authors.forename: R
authors.initials: R
authors.lastname: Milroy
authors.forename: I
authors.initials: I
authors.lastname: Nimmo-Smith
authors.forename: A
authors.initials: A
authors.lastname: Wright
authors.forename: R
authors.initials: R
authors.lastname: Tyrrell
authors.forename: K
authors.initials: K
authors.lastname: Holland
authors.forename: J
authors.initials: J
authors.lastname: Martin
authors.forename: J
authors.initials: J
authors.lastname: Bald
authors.forename: S
authors.initials: S
authors.lastname: Yale
authors.forename: T
authors.initials: T
authors.lastname: Miles
mesh_terms: D000293:Adolescent; D002648:Child; D003119:Color Perception Tests; D003124:Colorimetry; D005139:Eyeglasses; D006801:Humans; D055095:Optics and Photonics; D010468:Perceptual Disorders / Q000628:therapy; D014786:Vision Disorders / Q000628:therapy*