Source : Webster's Revised Unabridged Dictionary (1913)

Huyghenian \Huy*ghe"ni*an\, a.
   Pertaining to, or invented by, Christian Huyghens, a Dutch
   astronomer of the seventeenth century; as, the Huyghenian
   telescope.

   {Huyghenian eyepiece}See under {Eyepiece}.