Query About Monocular Double Vision. Ct?

Doctor, I'm Having Monocular Double Vision And Blurry Vision For 1.7-2.0 Years. I First Consulted An Opthalmologist Befote 1.5 Years. Then, The First Doc Diagnosed Me With Myopic Astigmatism in Both Eye. However, In Those Time, There Was No Cylindrical Power in My Left Eye And The Double Vision And Astigmatic Blurry Vision Were Only Present At Right Eye. He Alxo Examined Me With Slit-Lamp. He Prescribed Me Glasses, But His Prescribed Glasses Cannot Fully Eliminate The Double Vision.I Went To The Same Doc After One Year And Complaint About The Remnant Double Vision.Then He Rechecked My Eye And Told That The Remnant Double Vision Is Normal And Some Degrees Of Double Vision Will Remain Even After Wearing Glasses. Then, After 2 Months, I Went To An Different Doc And Complaint Him About The Remnant Double Vision Even After Wearing Glass. After Examining Me, He Say Same Talk As Like The First Doctor About The Remnant Double Vision. Why They Saying This?And Why They Didn't Recommend Me A CT?