Worked on both sides the spectacle cases are lined with felt and have a magnetic closure to keep your specs safe and unscratched. They will take a fairly good sized pair but if yours are particularly large you could repeat the chevron patterns at the sides (you should have plenty of thread but if not telephone me for more) or if they are small you could omit the chevrons.
The kits contain all you need to make a specs case, including the felt for lining and the magnetic closure with instructions for fitting it. If you like to make sets of things they go with the Scissor and Thread Cutter Pockets in Accessory Collections.
Worked from a chart in stranded cotton on size 18 canvas.