There is only 1 correct way to fit the glasses in the case. If you place the glasses into the case without folding the legs properly, they won't charge. If you try to force the glasses into the case, you may damage the case or the glasses.
1. Fold the left leg first.
Make sure the right arm (the one with the charging contacts) is folded second, so that it is the bottom-most leg when folded. See the image below.
2. Guide the glasses into the case.
Guide the glasses into the charging case, making sure the right leg (the one with the contacts) slides into the grooves first. Make sure the right leg is beneath the positioning tab, then set the rest of the glasses into the case. See the GIF below.
3. Check the positioning tab.
Check to make sure the right leg is completely beneath the positioning tab, as seen in the image below.
4. (Important) Seat the glasses into the case.
Push down on the left side of the frames to fully seat the frames in the charging case. They should "click" into place. See the GIF below.
The charging light on the case should flash white to indicate charging, or turn solid white to indicate the glasses are fully charged. If the light does not turn on, the case itself needs to be charged!
See the video below to watch the whole charging process in action:
For some glasses, following the above tips may not be enough because some prescription lenses may "stretch" the frames so they don't fit perfectly in the case. In order to overcome this, there is an additional trick to putting the frames in the case.
On the right of the frames, there is a small ledge. For some glasses, leaving a small gap between the right edge of the glasses and the charging case allows the frames to fit more snugly, as shown in the following picture:
For other glasses, it may be better to close the gap as shown in the following:
You may need to test on your particular pair to see which placement works better.