Common Cornflower (Centaurea cyanus) may be the plant on fol.10r of the Voynich manuscript. The mountain cornflower (Centaurea montana) has wider leaves than the common one - so it may have been 'the model' for the drawing. The Cornflower was used to treat conjunctivitis and as wash for tired eyes. I believe the root formations on the VMs drawing on fol. 10r are pretty good anatomical representations of eyeballs.