Carole,

How did it go when you tried John's suggestion of observing how your vision problems vary (or don't vary) over the course of the drug cycle?

Another thing you could try (as an experiment) is to change from taking one 25/125 tablet four times a day, to taking half a 25/125 tablet eight times a day. It might be a bit onerous, but it would just be for a few days. You could set up eight alarms on your mobile phone to remind you when to take the half tablet.

Jeff