13 Silly Mistakes You Won't Believe Made It Into Star Trek Movies
10. Kirk's Glasses Aren't That Valuable In 1986
In Star Trek II, Dr McCoy gives Admiral Kirk a pair of reading glasses for his birthday. While Kirk is a bit glum to receive them at this point, feeling like this is the Doctor's way of reminding him how old he is, the glasses themselves form an important part of the plot in Star Trek IV.
Once the crew of the HMS Bounty finds itself in 1980s San Francisco, they realise quickly that to get anything done, they'll need money. Kirk comes up with the bright idea of selling the very same glasses that McCoy gave him to an antique dealer, as by this stage they will still be very valuable.
He and Spock visit the dealer, who confirms that they are 18th century and quite valuable (then stiffs them on account of the broken lens). However, he may have been worse at his job than they knew. The style of glasses that Kirk is offering was not available in the 18th century, owing to the moulded plastic nose grip and temples. They are much more likely to be early 20th century glasses.
Frankly, the crew were lucky to get $100 for them.