Some general info about them in the following two links:

http://www.allaboutvision.com/contacts/extended.htm
http://www.contactlensdocs.com/Extended%20Wear%20Contact%20Lenses.htm

Popular extended wear brands in the following 2 links:

http://www.contactskiosk.com/contacts/t_Extended_Wear_Lenses.html
http://www.lenson.com/eu/extended-wear-lenses-c-26.html?osCsid=56dc5b03282117d9fc0763dd48631df0

An alternative type of lenses is rigid gas permeable. RGPs are not as an attractive option after the introduction of the latest soft lens material technology balafilcon A (silicone hydrogel) that compared to the older material technologies (like alphafilcon A) provide better gas permeability characteristics that are comparable to those of RGPs.

I use toric soft lenses as I have a combo of myopia/astigmatism in both my eyes. Up to now I have been using B&L's SofLens Toric brand that I have found to be much superior to others (like CIBA's comparable products) especially in comfort and quality of vision. The clearly better comfort is probably due to their market leading 66% water content (but, I guess, there is more to it than just that).

However, I am going to switch to B&L's new balafilcon A toric soft lens product named PureVision Toric, as it is said to be much superior, especially for extended wear style of use. SofLens is an extended wear contact lens product but it is recommended for continuous wear periods that do not exceed 1 week in duration. PureVision Toric can be continuously worn for up to 30 days.

I have to note here, that I have been continuously wearing my SofLens lenses for periods of up to 1 month, for the past 2 years, without any significant problems (always giving a 2-3 days break to my eyes inbetween). However, they did tend to get unconfortable after the first 2 weeks at which point I could go on wearing them by using rewetting drops every 2-3 days.

Read more info on B&L's great toric lens products here: http://www.bausch.com/en_US/ecp/visioncare/product/softcontacts/astigmatism.aspx

Technorati : Bausch, Lomb, balafilcon, contact lenses, lenses