...that i'm only an internal medicine intern, yet my chiefs and attendings are already asking me for eye advice. so the question that was asked to me was, what makes the new accuvue with hydraclear contacts so great?

I'm assuming you're talking about Acuvue Advance lenses, if not then ignore the rest of my post.

Acuvue Advance has a very high dk value (oxygen permability). It is second, I believe among soft lenses, only to Focus Night and Day. Most soft lenses that are regularly prescribed hover somewhere around 20, Acuvue Advance is about 80 while Focus N&D is about 140. There might be more to the lenses than just that, but I know that the dk value was one of the aspects that Vistakon pushed. That's my take on it.

If I'm mistaken on any of this, someone please correct me.

does a high dk value make CLs more comfortable?


I'm assuming you're talking about Acuvue Advance lenses, if not then ignore the rest of my post.

Acuvue Advance has a very high dk value (oxygen permability). It is second, I believe among soft lenses, only to Focus Night and Day. Most soft lenses that are regularly prescribed hover somewhere around 20, Acuvue Advance is about 80 while Focus N&D is about 140. There might be more to the lenses than just that, but I know that the dk value was one of the aspects that Vistakon pushed. That's my take on it.

If I'm mistaken on any of this, someone please correct me.

I'm assuming you're talking about Acuvue Advance lenses, if not then ignore the rest of my post.

Acuvue Advance has a very high dk value (oxygen permability). It is second, I believe among soft lenses, only to Focus Night and Day. Most soft lenses that are regularly prescribed hover somewhere around 20, Acuvue Advance is about 80 while Focus N&D is about 140. There might be more to the lenses than just that, but I know that the dk value was one of the aspects that Vistakon pushed. That's my take on it.

If I'm mistaken on any of this, someone please correct me.
The approximate Dk numbers are:

AV Advance - 90
Focus Night & Day - 175
O2 Optix - 138
Pure Vision - 110

While it is true that the higher the Dk, the more Oxygen permeability, that does not necessarily translate into increased comfort. That being said, I have had the most success with the Night & Day lens. I have heard that the Pure Vision is even more comfortable, but I haven't used it much since its return to the market. Friends of mine swear by the AV Advance saying its the best lens on the market.

The real issue with Dk is extended wear. There are some older studies suggesting that the min Dk needed for extended wear is 125. AV Advance is not marketed as an extended wear lens. Night & Day (30 days), Pure Vision (30 days) and O2 Optix (14 days) are all marketed as extended wear. The O2 Optix has only been approved for 6 nights while the other two are approved for the life of the lens (30 nights).

Hope that helps.

Ben

thanks ben!

I have problems with contact lenses because my eyelids are very close to my orbits. Every time I blink the lens moves a little bit. I have tried dailies, which are certainly better than permanent lenses, but does anybody know any better alternatives besides lasix??

I have problems with contact lenses because my eyelids are very close to my orbits. Every time I blink the lens moves a little bit. I have tried dailies, which are certainly better than permanent lenses, but does anybody know any better alternatives besides lasix??

lasik? lasix is 40 po qdaily, no? ;) just giving you a hard time. good question though, i'd be very interested in knowing the answer to this for myself.