I experienced the eyestrain and blurred vision and I asked for advice from ophthalmologist and started to take Vitamin D3. So that my eyesight got better. Now I take 2000 IU of vitamin D3 per day and try to get frequent exposure to sunlight. The few times I've run out of D3 and skipped the dose for a few days, I've noticed that the eyestrain and blurred vision return. Can too much vitamin d cause blurred vision?