If you had an eye tumor would it show on a brain mri scan?

Depends on size,loc: MRI's limited resolution in "standard" view can miss tumors <1 cm in size. Dedicated MRI of the orbits (eyes) can see tumors that are ~0.2 cm in size, but require a special order to perform. Also, the tumors show up in a way that can be confused with normal vitreous fluid in the eye, so often dye is needed, depending on location. Talk to an ophthalmologist about symptoms 2 c if MRI order's correct