Overview

While the crystalline lens of a young adult is colourless, as the owner ages, it starts to appear yellow. This yellowing of the crystalline lens means that it absorbs blue light and the elderly experience changes in their colour perception.

Traditionally, yellow lens glasses have been used to simulate this change. However, the results they produce are unsatisfactory and do not accurately show how vision changes with age. Dr Katsunori Okajima has now created a far more accurate optical filter that is used in these FVG-1 glasses, that accurately mimics the vision of the elderly as suggested by the two factor model.The graph below shows how using this optical filter compares to a yellow tinted lens lens.

Depending on the age of the wearer, the glasses can simulate the vision of someone between the age of 72 and 80, see chart.

Dr Katsunori Okajima of Yokohama National University: Comparing the Visibility of Low-Contrast Color Landolt-Cs; Effect of Agin Human Lens", Color Research and Application, 30 No.1, 5-12 (2005)

^ Back to top