You can size them to any pair of glasses.
Well, I have noticed that none of the glasses cases I own are big enough for my giant sunglasses! But my sunglasses most definitely deserve a case.
Soooooo....I made one myself out of Pacman fabric! Then i got carried away and made another out of tyedyed flannel.
The lining of the pacman one is yellow stretch fabric, and the lining of the tye dyed one is beige satin.
First, you must put your glasses down on a piece of paper and trace around them to get a general idea of how big the case will have to be. When you've got your glasses size, make a rectangle around it that's about 1 inch bigger than the glasses.
Next, cut out your pattern. Then, cut two panels with it out of the lining and out of the outside fabric.
Add a hem to the top of each fabric piece.
Then, sew them together as follows:
the outer fabric so that the right side is facing out (like you would a regular bag)
and the lining fabric so that the good side is facing in (so that the inside and outside will both show the right side)
Now, turn the outside fabric right side out, and put the lining in it, so that both the inside and the ouside show the right side of their fabrics.
Sew them around the top so that their "rims" are connected. Be careful not to sew them shut, though.
Insert your glasses and use!