Contact Lenses
Toric Lenses for Astigmatism
Toric lenses correct astigmatism by carrying different powers in different meridians. Because that correction only works when aligned correctly, toric lenses are weighted or shaped to stay rotationally stable as you blink.
Astigmatism means the eye's surface is curved more steeply in one direction than another, closer to a rugby ball than a football. Light therefore focuses at two different points rather than one, blurring vision at every distance.
Correcting it requires a lens with different powers in different meridians, and crucially that lens has to stay in the right rotational position. A spherical lens can spin freely without consequence. A toric lens that rotates puts the correction in the wrong place and vision goes blurry.
Manufacturers solve this with ballasting, thin zones, or truncation, all of which use the natural pressure of the eyelids during a blink to return the lens to its intended orientation. Fitting one therefore involves watching how it settles and rotates on your eye, which is why the assessment takes longer than for a spherical lens.
Questions and answers
I was told my astigmatism was too high for contacts.
That advice is often out of date. Toric soft lenses now cover a much wider range than they did, and rigid, hybrid and scleral options cover higher and more irregular astigmatism beyond that. It is worth reassessing.
Why does my vision fluctuate with toric lenses?
Usually rotational instability. The lens is settling in slightly different positions through the day. That is a fitting problem with solutions, not something to accept.
Are daily toric lenses available?
Yes, in a good range now, which combines astigmatic correction with the hygiene advantages of daily replacement.
Is astigmatism the same as keratoconus?
No. Regular astigmatism is a symmetrical curvature difference correctable with toric lenses. Keratoconus produces irregular astigmatism from a cone shaped distortion, which needs specialty lenses instead.
Talk to someone about toric lenses for astigmatism
Appointments are scheduled two per hour, so there is time to answer questions properly. Call (480) 706-3937 or request a time online.