Source : Webster's Revised Unabridged Dictionary (1913)

Sightless \Sight"less\, a.
   1. Wanting sight; without sight; blind.

            Of all who blindly creep or sightless soar. --Pope.

   2. That can not be seen; invisible. [Obs.]

            The sightless couriers of the air.    --Shak.

   3. Offensive or unpleasing to the eye; unsightly; as,
      sightless stains. [R.] --Shak. -- {Sight"less*ly}, adv.-
      {Sight"less*ness}, n.

Source : WordNet®

sightlessness
     n : lack of sight [syn: {blindness}, {cecity}]