Toric Soft Contact Lens
Contributor: Tressa Larson, OD, FAAO
Photographer: D. Brice Critser, CRA
Category: Contact Lens
Toric soft contact lenses have two powers built into them in order to correct regular astigmatism. The lenses generally have a laser marking to aid the clinician in evaluating the fit. In the Comfilcon® lenses pictured, there is a single marking at 6 o'clock on the lens (seen as a bright linear reflection as light artifact reflects off the laser marking in the picture). If the marking is rotated away from the 6 o'clock position, as in the second image, more analysis is required. If the marking stabilizes in that location you can note it and move on if the vision is good. However, if the vision is not acceptable, you can compensate the axis using the LARS rule- Left Add, Right Subtract. In this example, the lens is rotated about 15 degrees to the doctor's left - so if the original axis was 020, the new axis would be 035 (Left Add). If the location of the laser marking is unstable, you cannot compensate for that and you need to go to a different brand of lens since unstable rotation means unstable vision.
Ophthalmic Atlas Images by EyeRounds.org, The University of Iowa are licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.