So Tiffany (on FPN/Facebook) did a little googling when I bought up about using this as an eye dropper.
Apparently if you get it with the rollerball you can just swap the barrel on the two and be able to use the fountain pen as an eye dropper. And it's not like the ink window is going to hurt the rollerball any.
KarlBlessingYou will also need some silicon grease, and O-ring, and some epoxy to fill in the vent holes at the end of the rollerball barrel. A problem to be aware of with this conversion is that the pen tends to burp from time to time.
Apparently if you get it with the rollerball you can just swap the barrel on the two and be able to use the fountain pen as an eye dropper. And it's not like the ink window is going to hurt the rollerball any.