A transporter assistant with glasses
Glasses were a form of eyewear, an early way of correcting vision for those with eye problems. They were replaced by either corrective laser surgery, or special kinds of drugs and treatments developed through the study of medicine.
Glasses were worn by some in the 23rd century. A transporter assistant serving aboard the USS Enterprise in 2254 wore glasses while working at the transporter console. (TOS: "The Cage", "The Menagerie, Part I", "The Menagerie, Part II")
Lieutenant with glasses
A command division Lieutenant of the USS Enterprise who beamed down to the Terratin city on Terra 10 also wore glasses. (TAS: "The Terratin Incident")
Captain James T. Kirk was allergic to Retinax V, the conventional ways of correcting vision, so Dr. Leonard McCoy provided him with a pair of 18th century glasses. However, the glasses broke during the conflict with Khan Noonien Singh and his followers. (Star Trek II: The Wrath of Khan) Kirk would end up selling the glasses at an antique shop on 20th century Earth in exchange for currency needed to accomplish their mission to save Earth in the future. (Star Trek IV: The Voyage Home)
Kirk's glasses, broken
Glasses were also common on Malcor III. Both Krola and Lanel wore them. (TNG: "First Contact")
A 'bifocal visual aid'
In 2368, several artifacts were recovered from a cavern underneath the Earth city of San Francisco. Among them was a pair of glasses which lieutenant commander Data described as a "bifocal visual aid." (TNG: "Time's Arrow")
In visions received from the Prophets, Benjamin Sisko's 20th century personna Benny Russell wore glasses. (DS9: "Far Beyond the Stars")
Appendices
Related topics
Background
A librarian with glasses in a deleted scene from Star Trek: Insurrection
In a deleted scene in Star Trek: Insurrection, a librarian serving on the USS Enterprise-E (played by Lee Arnone-Briggs) wore glasses.