I just cleaned the lenses and the goggles very well, them laid in a circle of 3-D fabric paint along the inside edges of the goggle lenses. Some would say use GOOP or RTV, but the fumes, even long after it has cured, irritate my eyes. Next, I gently laid in the lenses. The adhesive only holds the edges, and yes, there's gaps where the lenses touch. Fabric paint is sloppy and wet while setting, don't use much. You can add more later to hold better and to decrease side gaps. Make sure the goggles are sitting where they can rest without movement for about six hours. If the paint smears while you're setting in the lenses, you can rinse everything off and begin again. I used bright red, and yes, I can "see" it at the edges of my vision. Next time I get new glasses, I'll make another pair.
I don't have pictures handy, the box of goggles and stuff is buried outside.
we were riding the crest of a high and beautiful wave. . . .