Can decompression surgery for chiari malformation 1 relieve vision problems/issues (like blurry/double vision or seeing flashes) caused by chiari?

Depends: The goal of Chiara surgery is to restore the normal pattern of CSF flow & thereby prevent further deterioration of the visual (& balance) symptoms of the ACM malformation. Whether this helps existing symptoms depends on how long those symptoms have been present, the type of surgery contemplated, it's success rate, age, & underlying factors. It's a question to ask the neurologist who knows you best