Hi
No pilot flies with one eye closed therefore any deficiency in one eye will be cancelled out by the other as long as your overall acuity is 6/6 with or without correction you will be fine...
You do not mention your prescription here are you able to post it? Your astigmatism can be up to 3.00 diopters in reality. Its 2.00 for initial however if you are higher than 2.00 at initial you may be granted a Class 1 With Deviation until you qualify / renew where the deviation will be removed if the astigmatism falls 3.00 or below.
I've had laser surgery (Lasik) to correct an astigmatism of -3.75 which was well out of any limits set by CAA. Its also corrected my prescription of +2.00 and -1.75.
If I can help with anything else drop me a PM... As I've been through the system in the last year having failed my Class 1 last year and passed it this year..
Hope this helps
JONATHAN