Method of calculating visual distance of spectacle lens, visual distance display device and method of evaluating spectacle lens

摘要

PROBLEM TO BE SOLVED: To provide a visual distance calculation method of a spectacle lens by which a visual distance matched to consciousness of a user can be accurately computed and the user is enabled to comprehend the visual distance in wearing spectacle lenses, a visual distance display device and an evaluation method of the spectacle lens.SOLUTION: In the case where a wearing frequency of a spectacle lens for a user at any arbitrary coordinates is defined as A (diopter) and a reference distance frequency in which the user can focus a reference distance C (meters) is defined as B (diopter) when the user watches a distance (such a distance is defined as a reference distance hereafter), a value obtained by a following expression can be determined as a visual distance X (meter) in a visual line direction passing any arbitrary coordinates (Z, Y) where the spectacle lens is located.