I've noticed that some funny words only exist in English in the plural. We can hold a pair of scissors, but there is no such thing as a single scissor. And we put on our pants, one leg at a time, but still that one leg is in our pants, not our pant.
Of course, there can be scissor marks on a piece of paper, or we can notice the stain on our pant leg. That sounds singular. But really "scissor" and "pant" are here used as adjectives, and thus in English they are neither singular nor plural.
And even if only one lens gets crushed, you have still broken your glasses. Again, that word only exists in the plural (when it means the things you put on your nose to help you see).
How many other words do we use that can only be used in the plural?