Modelling of Eye plaque

Dear Experts,
I want to model a CCB Eye Plaque (a concave geometry) in FLUKA.
see the geometry:
How to model this kind of geometry?

Any suggestions will be helpful for me.

Thanking you in advance.

Dear @ArghyaC,

As far as I understand it, the plaque is just a spherical cap, then I would say that a sphere cut by a plane should be enough to model it.