Do long wavelength pass filters improve low vision performance?
It has been suggested that the wearing of band-pass tints may improve the contrast performance in certain ocular conditions. We examined this by measuring grating visual acuity (VA) for targets of various contrasts. The benefits of Corning CPF 511, 527 and 550 lenses, and neutral density (ND) filters were examined with and without the presence of glare. Generally, patients with anterior sector conditions showed improved performance with band-pass filters (not with ND filters). It is suggested that the filter reduces the scatter within the ocular media. People with retinitis pigmentosa or diabetic retinopathy rarely benefited. The CPF 511 most frequently improved VA followed by CPF 527 and 550 respectively. We suggest that a condition of glare is incorporated when assessing suitability with tints.
Leat
S J
SJ
Laboratory of Experimental Optometry, University of Wales College of Cardiff, UK.
North
R V
RV
Bryson
H
H
D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D007909:Lenses; D008027:Light; D010364:Pattern Recognition, Visual / Q000502:physiology; D012542:Scattering, Radiation; D015354:Vision, Low / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology