Hello,
First of all, Yashar koach for your willingness to donate. Sometimes, corneas are indeed not suitable for transplantation, but the desire and readiness to donate are a great merit for both the deceased and the family.
From a halachic perspective, many authorities hold that due to the small size of the corneas, they do not require burial. However, both from an emotional standpoint and a halachic one, it would not be appropriate to simply discard them.
Therefore, the common practice is to contact the local chevra kadisha (burial society), and they will arrange for the corneas to be buried.
Wishing you all the best and happier occasions ahead,
Rabbi Yuval Cherlow
Rabbi Cherlow is the Head of the Ethics Department at the Tzohar Rabbinical Organization.
For additional Reading: