There are three main reasons: First, tradition. Glasses have always been regarded as a boutique series, and generally belong to luxury goods like jewelry and cosmetics.
Second, the glasses industry and taxes are relatively high.
Third, optical shops are generally located in better locations, require more technicians and have higher actual costs.
The above three points determine that the price of glasses is more expensive.
Of course, schools and communities also have some glasses with lower prices, which are related to the above two reasons.