Optometrist describing eye health: Astigmatism. Dr. Buettner from Ottawa is a member of OSI, Canada's Largest Network of Optometrists, www.opto.com, with over 750 clinics in Canada. Other informative videos now (or soon to be) available: Amblyopia, Are Contact lenses for me, Astigmatism, Cataracts, Children's vision, Colour deficiency, Conjunctivitis, Contact Lenses' wear and care, Diabetes, Dry eye, Eye coordination, Eye examination, Farsightedness, Floaters, Glaucoma, Macular Degeneration, Nearsightedness, Presbyopia, Strabismus, Types of Contact lenses, Vision and computers and UV Rays