Method Optimization for Evaluating Contrast Sensitivity
Research type
Research Study
Full title
Contrast Sensitivity Measurement Validation Testing Program-Phase 1 – Test Resolution Determination
IRAS ID
362627
Contact name
Michel Guillon
Contact email
Sponsor organisation
Ocular Technology Group-International
Duration of Study in the UK
0 years, 6 months, 1 days
Research summary
Modern intra ocular lenses (IOLs) that replace the natural lens of the eye after cataract extraction include designs that correct vision at all distances from far to near. A drawback of some of these designs is that some patients complain of glare under nigh time vision conditions. In order to quantify the glare disability associated with such IOLs the International Standard Organization (ISO) has developed a testing standard (ISO 11979-7 2024) requiring testing of contrast vision in the presence of glare of relatively low level. The requirement of the standard being to use glare sources that produce a contrast loss of 0.1 log contrast (equivalent to one line loss of contrast on tests that usually contains more than ten lines of decreasing contrast).
Two different methods are used to test contrast, sinusoidal glare (usually lines of a given thickness that varies in contrast from light to dark) and letter glare (letters of constant size but of decreasing contrast). The objective of the study is to determine the effect of three low levels of glare on achieving ISO recommended glare under low light condition. Three tests will be assessed, two with sinusoidal contrast and one letter contrast test.
A population of young presbyopes, which is the closest population to IOL patients in term of optical characteristics (pupil size and optical clarity) will be tested with the three methods. The participants will attend the clinical site on two occasions. The first visit, will be a screening, enrolment and test familiarization visit. The second visit will be the test visit when the participants will undergo the three tests, the order of the tests being randomized to avoid order fatigue bias.REC name
London - Riverside Research Ethics Committee
REC reference
25/LO/0724
Date of REC Opinion
18 Nov 2025
REC opinion
Further Information Favourable Opinion