Ok and thanks for your input.Well, based on the information's provided i am suspecting that your base line BP is low, and when you change position fast that makes you prone to orthostatic hypotension causing such dizziness and blurring of vision. There are various causes of such orthostatic hypotension like dehydration, cardiac issues and poor nutritional intake etc. I suggest you to see your doctor for its confirmation. He will check your B.P at sitting and standing position and will run few tests. In the mean time keep yourself well hydrated and use elastic stocking while you are at home to prevent pooling of blood in your legs, hence avoiding episode of dizziness.Regards.
Use reply to let me know if you have further questions.