You are suffering from high-myopia
as described by you. The retinal detachment
is a very common complication of high myopia. In my opinion, you should not go for LASIK laser
as you are supposed to be having a weak retina. Repeated interventions in the eye in high myopic cases with retinal changes should be avoided as much as possible.
Visibility of sclera is due to bigger axial length of the eye which is always present in high myopic cases.