Survey on problems associated with the use of progressive addition lenses (pal)

Abstract

Progressive addition lenses (PAL) are meant to provide clear and comfortable vision to wearer at every given distance. But it is increasingly becoming common to hear PAL wearers expressing one form of misgiving or the other over their effectiveness. This Lagos based study of 106 PAL wearers revealed that most of the problems associated with the use of PAL have to do with precision in mounting lenses to specification using appropriate data: Interpupillary Distance (IPD); Segment Height (SH); Optic Centre of Lenses (OC); Geometric Centre of Frame(Mid-Datum Depth). 15subjects (14.2% of study population) have discomfort with use of PALdue to wrong placement of segment height, while 8 subjects (7.5%) have difficulty using PAL due to inaccurate application of IPD resulting in decentration with concomitant prismatic effect. Statistical analysis of data using Chi Square revealed that the various complaints about use of PAL had no relationship with age of wearer. This study underscored urgent need for the establishment of formal training school for practicing dispending opticians in Nigeria.