Belay glasses for climbing

When I belay my climbing partner, I get a stiff neck from craning my neck to look upwards.
I saw other people with belay glasses, but was amazed how expensive the glasses were.

So I thought I was being clever and bought a pair of really cheap book reading glasses from Amazon. They arrived, but it turns out you can't flip the direction.

So instead I cut out the prisms and surrounds, and designed my own glasses using the arms.

The glasses I used are http://amzn.eu/3KMoJaU
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