I have astigmatism, and I use bitoric rigid gas permeables. I’ve had them since I was 14 or so. I’m not sure whether your concerns are for hygiene, safety, or cost, but in my experience:
taking care of them is easy. The graphic pictures of diseased eyeballs were enough to make me take care of them.
they make you susceptible to getting random dust particles and jagged boulders in your eyes (okay, okay, they just feel like jagged boulders), but they’re no less safe than glasses on your face. They’re arguably safer-- my SO had a nice scratch on his face where the nosepad of his glasses dug into his flesh when someone ran into him hard.
they cost about the same as glasses and last about as long. Just don’t lose them down the drain or drop and immediately step on them, like I have.
Cal, how is an astigmatic lens held on the cornea so it doesn’t rotate? That would make the cyl axis change and render the correction useless or worse.
…apparently they’re weighted somehow to keep the axis right.
FWIW. I’m 49, astigmatism, and got my first contacts when I was 48. For the first month I walked around absolutely atounded, regretting that I hadn’t gotten contacts 20 years ago! They amaze me still…and when I take them out and wear my regular glasses I can’t believe how small the field of vision is!
Thanks so much for the comments, everyone! I’ve been away from the Dope for a few days (hella busy) so I just sat and read them in one go, and it’s made me rethink this. It sounds like they could have benefits that go beyond just looking better - or rather “not looking too different”, which I suspect is the real game here - and that appeals to the rational part of my brain. I’m going to talk about this with my husband, I think we should at least make an appointment with an eye doctor to find out if flodjunior is a candidate and what the pros and cons are.
For the record, he doesn’t do any contact sports, and he is very careful with his glasses. He’s only broken them once, in an incident that absolutely was not his fault, and he was embarrassed about that! I’m a bit concerned about the dust-in-the-eyes issue, as he already complains about that when he rides his bike, but maybe a pair of those curved sunglasses racing cyclists wear would help?
Eggerhaus is correct. The lower edge of a toric contact lens is thicker and heavier than the upper edge. Gravity and the motion of blinking make sure the lens is oriented correctly. It’s simple and ingenius. If you wear toric lenses overnight, it often takes a few blinks to get them straight when you wake up in the morning.
As others have noted, a toric lens is thicker on one side than the other. But weight doesn’t keep it properly oriented. There isn’t enough weight, and the lens has too much resistance to rotate very freely on the eye. It’s the force of the closing lid on the lens that constantly re-orients it with the thicker side down. Gravity is a negligible factor. As One Cent notes, a few blinks sets them straight. If it were due to gravity alone (or even primarily), you wouldn’t have to blink.
I would imagine the thicker part of the lens would not only be heavier, but have different optical properties as well. How do the lens makers keep those two effects separate?
A contact lens usually ranges in diameter anywhere from 12 to 14mm. Of that, only the central 6 or 7 mm is actually used for refraction - the part over the pupil at largest dilated size. So there’s a substantial ring of material that serves no optical purpose, but simply keeps the lens comfortable (by providing a gradual slope to the thicker center), in place, and (in the case of toric and bifocal contacts) properly oriented.
