
Contact Lenses (Soft Toric) -- RFC
OK, I've just gotten soft toric contact lenses (I'm a first time contact
wearer) and I'm wondering what experiences others in net-land have had with
these little beasties.
"Toric" lenses are desgined for people with astigmatism, where it is crucial
that the angle of rotation of the corrective lens with respect to the eye
remain constant. (Astigmatism is the term used to describe an eye which is
not perfectly spherical. To correct an astigmatism, the corrective lens
must be rotated to the "proper" angle with respect to the eyeball.) With
glasses, this is never a problem since the glasses are supported directly by
your nose and ears, and each corrective lens cannot rotate with respect to
the eye it corrects.
With contact lenses, however, each individul lens CAN rotate with respect to
the eye it corrects. A normal contact lens can rotate a fair amount,
effectively destroying the corrective effect for that eye.
"Toric" contact lenses employ various methods to ensure that the lens always
remains rotated to the proper angle with respect to the eye. One brand I
tried used "thin zones" in an apparent attempt to force the contact to "map"
itself to the eyeball in the proper corrective position (that brand didn't
work for me). The brand I am currently wearing apparently uses a "weighted"
design, whereby the intended bottom of the lens is somehow heavier or
thicker, and automatically rotates the lens into the proper position.
I particular, I am wondering:
1. What is the typical "comfort" break in period for new contact
wearers. How long can I expect it to take before I don't really
notice that I have the contacts in -- how long before they are
comfortable? Or will I always notice them to some degree?
2. How effective have you found the "toric" contact lens method of
correcting for astigmatism to be? Do your lenses remain stable
throughout the day, or do they occasionally fluctuate and force a
"blinking bout" to stabilize them? Have you had experience with
more than one type of toric lens ("thin zone" vs. "weighted" toric
lenses)?
3. With "weighted" toric lenses, I've noticed that the orientation of
my head can apparently affect the rotation of the lenses, thus
imparing my vision. (For example, if I lay down to take a nap, my
vision is very blurred when I first sit up. After 10 or 20 seconds
of blinking my eyes, I can re-stabilize the lenses. Should this be
happening?)
4. What of gas-permeable (hard) lenses? I've been told they actually
re-shape your eye over the break in period so that they effectively
REMOVE the astigmatism. If you stop wearing gas-permeable contacts,
your astigmatism will return over days or weeks.
5. How much effect does living in a relatively arid environment
(Colorado front range) have on wearing contacts?
6. After converting from glasses to contacts, how sensitive are your
eyes to wind and small breezes that would have previously been
blocked by the ever present glasses?
7. Can I be an astronaut, or am I restricted to glasses as my only
method of vision correction in a zero G environment?
Thanks for your comments,
Brent Geske