The eyeglasses scene doesn't make sense.
I can buy Kirk questioning their presence in his 23rd century (where vision problems don't require mechanical eyewear).
I can buy the fact that eyeglasses are a rare sight in everyday life in Kirk's time.
But I don't buy Kirk needing McCoy to explain how they function. Certainly Kirk is vaguely familiar with photos of people from history, and there are millions of such photos of people wearing eyeglasses. Kirk should know what those things are, how they were worn. It shouldn't be a mindboggler for Kirk.
Actually, they hadn't established it as 23rd century at the time and dialogue suggests the 22nd century. Which actually strengthens your point, being only 200 years rather than 300 years removed, but just mentioning that 23rd century was not established until WOK, a long time after Space Seed.
Anyone that idolizes Abraham Lincoln would certainly know what glasses are for and how to use them, furthermore anyone who knows about the shoot out at the O K corral in Tombstone would know about them.