Has anybody experienced changes in vision during a DMSA chelation cycle?

I'm doing my third cycle of 4 days/3 nights, and in each cycle by the third day my vision starts to get intermittently blurry. I've been taking an equal amount of time off between cycles.

I'm taking the basic anti-oxidants and fatty acid supplements that Cutler recommends plus plenty of magnesium and three liters of water per day. I follow the same supplement regime during the off cycle.