Persol Ratti 58230 - Arnold Schwarzenegger - Terminator 2: Judgement Day
The Persol Ratti 58230 sunglasses in the film have a rounded, black frame and dark lenses. The brow line across the upper half of the frame is slightly thicker than the rest of the frame.
There are two vertical lines, a signature design element of many Persol sunglasses. These lines are part of the Meflecto system which gives the frame extra flexibility.
Persol is one the oldest sunglass brands, formed in 1917 by Giuseppe Ratti, and until it was acquired by Luxoticca in 1995, it was operating under the original trade-name Persol Ratti.
You might be able to find these vintage Persol Ratti 58230 sunglasses online, there are usually a few on eBay, or ask specilalist vintage eyewear stores.
Magnoli Clothiers offers a replica on eBay for $89.
In the same film, Linda Hamilton as Sarah Connor wears Matsuda 2809 sunglasses.
Terminator 6: Dark Fate
In the 2019 film Terminator 6: Dark Fate, a CGI generated, augmented reality version of the old Terminator appears, wearing sunglasses that closely resemble the Persol Ratti 58230 but are slightly different.
Reference: Persol Ratti 58230, black frame