Updated: Feb 4
Acceptable positioning for a normal spherical lens might not be
acceptable for a VFL3 lens.
Most would agree that a somewhat high riding, upper lid attached fit would be a good situation for a spherical lens. A high riding, lid-attached VFL3 will usually result in fluctuating distance or blurred distance vision. Low or lateral decentration will also result in an equally poor result. The ideal position for a VFL3 lens would be centered over the pupil with minimal displacement during blink. Minimal displacement is defined as lens movement sufficient to promote tear exchange without substantial fluctuation in vision. This usually means an intrapalpebral fit. The fluorescien pattern should represent central clearnace, thinning to intermediate alignment and a progressive band of edge lift.