Re: Gas Permeable Hard Contacts Scratches



On Jul 3, 2:39 am, "Mike Tyner" <mty...@xxxxxxxxxxxxxx> wrote:
"Noke" <gad.g...@xxxxxxxxx> wrote

In other words. Even the furrows with polished edge will not do good
and one has to replace the entire lens everytime there is any trace
of scratches in the gas permeable hard contacts?? Thanks.

Not in my opinion, for what that's worth.

-MT

 in messagenews:bdfff537-fddc-4769-b817-fe0797259a79@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Jul 2, 9:08 pm, "Mike Tyner" <mty...@xxxxxxxxxxxxxx> wrote:





It's like the furrow a plow leaves. The material you remove from the
furrow
forms ridges on either side.

The discomfort of "scratched" lenses comes from the ridges, not the
furrow.
Anything that scratches will open the epithelium so germs can penetrate.
Ulcers usually start from broken epithelium and it doesn't really matter
what caused the break. And one good way to get ulcers is to scratch the
epithelium then keep it covered with a nasty contact lens. Normally ulcers
are prevented by the cleaning action of blinking and the antibacterial
lysosyme in tears.

Polishing removes the ridges, along with calcified deposits and other
"protruding" imperfections. To remove the furrow, you'd have to resurface
the lens completely, reducing its thickness uniformly to match the deepest
scratch. That's very difficult to do with a polishing pad; you'd want a
surfacing tool and you'll still break some lenses.

The furrows aren't uncomfortable, especially after they fill up with mucus
and debris and bio-junk. That also creates a warm gooey bed for
cultivating
bacteria and fungi.

Scratches that are "too deep to remove" will still feel better after
polishing. They can also be full of polishing compound and ground-up lens
material for a while.

-MT

About the furrows that can cultivate bacteria and fungi. Can't
cleaning
the lens each night remove the contents in the furrows? What would
it take to remove it? I ordered a pair of gas permeable hard contact
from a manufacturer. The right side doesn't have scratch, but
unfortunately, the left side has a scratch in the middle. They
polished
it and there is still a trace of the scratch and they won't replace
it.
I can wait a week and order elsewhere but my present contact even
has more scratches (about 20). So I am wondering whether to get
it now or wait one more week for a new lens from another manufacturer.
The decision depends on knowing whether a single furrow is harmful.
Usually what would it take to remove the contents in the furrows like
polishing compound and ground-up lens material? What ingreidents
are polishing compound made of? Is it harmful to eyes? How
about the ground-up lens material. Can it cause scratches in
the eye? Thanks.

Noke


"Noke" <gad.g...@xxxxxxxxx> wrote in message

news:7592be83-840f-4bc1-89ce-ef56f835713a@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Hi,

When gas permeable hard contacts get scratches. What
actually happens to the lens? Can anyone point me to any
site with magnified view of a lens surface? I'd like to understand
what goes on when polishing is done to "remove" the
scratches. The technician said some scratches are deep
and can't be removed. Can these cause corneal ulcers?
How doe scratched lens surfaces damage the cornea?
I'd like to kinda imagine what goes on between the cornea
and lens with scratches and how does the frictions or
contact occurs. Thanks.

Noke- Hide quoted text -

- Show quoted text -

In other words. Even the furrows with polished edge will not do good
and one has to replace the entire lens everytime there is any trace
of scratches in the gas permeable hard contacts?? Thanks.

Noke- Hide quoted text -

- Show quoted text -

.



Relevant Pages

  • Re: Gas Permeable Hard Contacts Scratches
    ... furrow. ... Anything that scratches will open the epithelium so germs can penetrate. ... epithelium then keep it covered with a nasty contact lens. ... Polishing removes the ridges, along with calcified deposits and other ...
    (sci.med.vision)
  • Re: Gas Permeable Hard Contacts Scratches
    ... The discomfort of "scratched" lenses comes from the ridges, not the furrow.. ... Anything that scratches will open the epithelium so germs can penetrate. ... epithelium then keep it covered with a nasty contact lens. ... Polishing removes the ridges, along with calcified deposits and other ...
    (sci.med.vision)
  • Re: Gas Permeable Hard Contacts Scratches
    ... It's like the furrow a plow leaves. ... Anything that scratches will open the epithelium so germs can penetrate. ... epithelium then keep it covered with a nasty contact lens. ... Polishing removes the ridges, along with calcified deposits and other ...
    (sci.med.vision)
  • Re: Starburst like scratches on lenses
    ... lens was smashed into. ... The miscellaneous slightly curved scratches are from ... The glasses were face down on possibly a sidewalk or some similarily gritty ... I would attribute the issue to stress in the lenses by external factors; ...
    (sci.med.vision)
  • Re: Gas Permeable Hard Contacts Scratches
    ... furrow. ... Anything that scratches will open the epithelium so germs can penetrate. ... epithelium then keep it covered with a nasty contact lens. ... That's very difficult to do with a polishing pad; ...
    (sci.med.vision)