The best replacement for cornea is conjunctiva.

The best alternatives to cornea are rated as following:
★★★★★  conjunctiva
★★★★  sclera
★★★★  lens
★★★  retina
★★  pink eye
★  iris
  scleral tunnel
  pupil

Your alternative for cornea is not listed? Suggest!
Speaking about cornea, one probably shouldn't forget about donor cornea.

Other search terms related to cornea and their ratings are:
★★★★★ donor cornea
★★★ intralase
You have in mind a companion for cornea and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of cornea in all years. Click on graph for more.
cornea
conjunctiva
sclera