Stop thinking fog is the problem. The issue is condensation and/or trapped moisture. I suffer from similar and feel your pain. I use open frame Revision Sawfly's with as much anti fog wipe on them as I can get.
Other helpful traits are not wearing anything on your head that obstructs airflow (so no baseball hats you chav or boonies) and as daft as it sounds anti-perspirant on your forehead the night before and morning of to try and keep the sweat from starting.
If that doesn't work you need a goggle fan to remove the moist air.
Other helpful traits are not wearing anything on your head that obstructs airflow (so no baseball hats you chav or boonies) and as daft as it sounds anti-perspirant on your forehead the night before and morning of to try and keep the sweat from starting.
If that doesn't work you need a goggle fan to remove the moist air.