What should I do if I have increasing irritability, occasional blured vision while taking effexor (venlafaxine)?

Call your physician. Taking any new medication that is followed by significant and unexpected symptoms, is best dealt with by immediately calling your physician. Most cases would result in advice given to the patient to stop or cut back on the medication, and to also consider another medication and other approaches for the patient's initial needs.
Drug effects . Side effects of antidepressants can cause blurriness of vision and as the dose increases this can get worse. Seek advice from the prescribing physician.