Select the most appropriate word to fill in the blank.
He has ______ vision because of his illness.

When referring to medical conditions where sight becomes unclear or fuzzy, the correct and standard term used is "blurred vision".
"Obscured" means hidden from view by something else.

"Unfocused" means not adapted to focus.

"Faded" means having lost color or clarity over time gradually (usually for objects, memories, etc.).