This is a common posting. The common causes: regular or irregular corneal astigmatism, lens problems like cataracts, debris like blood in the vitreous or abnormal macula. For people that wear glasses: improper glasses prescription or poorly fitting or manufactured glasses.
You would need to see a Eye MD ophthalmologist that specializes in corneal disease. Your tests would need to include a cornea topography test. Also macular OCT. Monocular diplopia corrected by looking through pinhole is usually cornea problem. Rarely anxiety.