Gasset A R, Houde W L
Ann Ophthalmol. 1978 Nov;10(11):1475-7.
Problems with the N series were mainly due to poor or viable visual acuity that could not be rectified by correcting the residual refractive error in spectacle overrefraction. The error lay mainly in the design of the lens and the fitting rationale. The introduction of lenses (B3 and F3) with base curve and power that adequately covered a wider range of aphakic eyes has solved the fitting problems in most cases. These have been done without sacrificing the simplicity in fitting. Most eyes can be fitted using the B3 series for corneas flatter than 43.00 diopters and the F3 for steeper corneas. The clinical application of the J3 has been found in our hands to be nil. Availability and reproducibility of these lenses are reasons for our preference to fit them for noncontinuous wear in aphakia. In addition, they were found to be a very safe and efficacious correction for the aphakic eye.
