Standard Soft Toric Lenses
Any form of corneal ectasia or irregularity will result in significant levels of astigmatism. This can often be difficult to fit with standard lenses, however, there are a few types which can be successfuly worn. In mild cases they can be quite successful and can are easier to handle, hygiene is also better due to the regular replacement. Lenses can be monthly, three monthly or six monthly disposable, which also makes it easier to change the prescription as be when needed.
It is often worth a try with these lenses to see if any decent level of vision can be obtained. For astigmatism above -6.00 dioptres, however, they are more likely to be unstable and inadequate.
As a general rule the prescription range would be from -20.00 to +20.00 and up to -6.00 in 5 degree steps of astigmatism.