Sana Kanwal, Hina Sharif, Muhammad Kashif Habib.
Determining Effect of Filters on Color Vision and Contrast Sensitivity among Low Vision patients: a Cross-Sectional Survey.
Al-Shifa J Ophthalmol Jan ;15(3):43-51.

A cross-sectional study was conducted in low vision department of Al-Shifa Trust Eye Hospital to assess difference in contrast sensitivity and color vision among low vision patients without filter and with yellow or pink filter. Diagnosis of each patient was enrolled provided by senior Ophthalmologist. Pelli-Robson contrast chart and AHRR color vision test were used for study. Procedure followed at first without using any filter then yellow filter and at the end with pink filter. Patients responses were noted.

PakMediNet -Pakistan's largest Database of Pakistani Medical Journals - http://www.pakmedinet.com