Four different frames are tested here: frame 1, frame 2, frame 3 and frame 4.
These frames are all designed to be used with glasses that have an adjustable lens, such as those in eyeglasses or contact lenses.
Each frame has an adjustable-lens design that can be adjusted to match the shape of your head.
Frame 1 is the most comfortable and most flexible.
Frame 2 is the simplest and most practical.
Frame 3 and 4 are more flexible, but are less comfortable and are not recommended for people with narrow or narrow-angle vision.
If you need a frame with a fixed lens, frame 1 is probably the best choice.
Frame 2 and 3 are both comfortable and versatile.
Frame 4 is the best compromise between comfort and flexibility.