This otherwise unnamed character had a significant role in the first origin story of Cyclops. Apparing in "X-Men" vol. 1 #39 (December, 1967). The Optometrist held an office in New York City. He was contacted by Sunset Orphanage and asked to examine Scott Summers, a teenaged orphan. Mr. Lamb, a supervisor, started escorting Scott to the doctor's office. The Optometrist continued examining his new patient for months.
Scott had been complaining of recurring headaches. The Optometrist soon noticed a "weird glow" in the eyes of the boy. The doctor provided Scott with various sets of glasses. But none seemed to do the job. Except a pair "containing bits of Ruby Quartz". Which seemed to cure the headaches. From Scott's perspective, the glasses helped him control his emerging powers. As the glow started being followed by energy blasts.
The Optometrist suspected that his patient was a mutant. Sending a report on the subject to the FBI. It was one of the earliest leads on mutants reaching the attention of Fred Duncan. One day, Scott went missing just before a visit to the doctor's office. Professor X, an associate of Duncan, visited the Optometrist to learn more about the missing boy. The Optometrist took the opportunity to confide his concerns about mutants. Did they "pose a deadly threat", or not? Xavier did not bother to answer the man.
"X-Factor" vol. 1 #35 (December, 1988). mentions (but does not depict) the Optometrist. He is mentioned as a "specialist in Washington" who discovered that Ruby Quartz lenses count control Scott's headaches. The relocation of his office might be based on a misreading of the original issue, where scenes took place both in New York and Washington. But the dialogue of the original story identified the Optometrist as New York-based. A peculiar retcon of that issue was placing Scott's visit to the doctor further in his past. The Scott depicted in the flashback is at most 12-years-old.
A number of later retcons have established that Scott had been having his headaches for years. Which isn't much of a contradiction. But at least two stories feature early versions of the glasses:
* "X-Factor" vol. 1 #39 (April, 1989) features Mister Sinister providing Scott with a pair of Ruby Quartz glasses. Claiming it was one way to hold back Scott's optic blast. Scott had no recollection of the event. No mention of how did Sinister reach this solution.
* "Classic X-Men" #42 (December, 1989) has Scott already suffering from headaches. Dr. Robyn Hanover mentions that only Ruby Quartz can relieve his pain. Though Scott does not yet wear glasses regularly. No mention of who came up with this solution.
The stories in chronological order (not publication order) would have Sinister provide Scott with his first pair of glasses. Then Scott being able to operate without glasses. Then Scott going to the Optometrist and ending up with a second pair of glasses. Which is rather peculiar.
There is a theory that the Optometrist is an early guise of Sinister. But there is no story confirming this.