What is the difference between single-vision and bifocal/progressive lenses?
Lens Thickness/ Lens Index
How to choose lenses?
What coatings and add-ons do you offer for your lenses?
Difference between Spherical Lens and Aspherical Lens
What're the difference between Tint lens, Photochromic lens and polarized lens?
Photochromic & Transitions® Lenses Introduction
Do you have prism lenses?
Can I buy lenses only to fit into my old glasses frame?
Do the lenses include any coating?
How to use progressive glasses?
Do you offer bifocal or progressive lenses?
What is the material of your lens?
What's the difference between basic coated lenses, standard coated lenses and blue-light blocking lenses?
How to change the lens of safety/sport glasses?
Which kind of lenses are free?
What type of bifocal lens do you use?
Spherical VS Aspherical Lens (video)