I am living with tumor in right eye for the past 14 years. neuro sugens has operated twice. 1st time operated in 1998 and removed 90% tumor and 2nd time operated in 2008 and not removed 10% of tumor since my vision was 6/6. again the eye is bulged and vision also reduced 50%. doctor has advised for a gamma knife. can i go for that. can i get the vision back (6/6) and what are the side effects.