Sometimes due to a heart disorder the blood backs up in the vessels and causes edema (fluids leaking into the vessels) and cause swelling of the peripheral extremities, but almost always that involves both legs. At the top of a diagnosis would be blood clots: a clot in vessel to the left ankle for the swelling of the left ankle. A blood clot to the eye retina can cause a blurring of vision.
You should be seeing a doctor and the very least you should take an aspirin. That will help prevent clotting.
Hope this helps, and if you have any further questions or comments you are welcome to reapond. Take care,