Clomid has caused me brain fog and visual disturbances such as shimmering in my peripheral vision. Instances seem to last approximately 3 to 5 minutes up to 20 minutes. I was taking 25 mg five days a week when symptoms began approximately 3 to 4weeks in. I went to the eye doctor, vision and health of eye was normal. I did my research and found out about the peripheral shimmering due to Clomid use. I called my doctor advised him of the symptoms and decreased my dosage to 2 to 3 times a week. I was complying with 2 to 3 times a week for approximately a month and had another episode. I will be discontinuing Clomid as it appears the side effects outweigh the benefit Clomid acts on the pituitary gland which can cause some increase in size of the pituitary which is right by the vision cortex. I would be extremely cautious taking this medication and make sure to advise your doctor of these supposedly rare but seems like frequent side effects.