Yes, it can.
Theoretically, the nerves on your neck which connects your eyes and the visual area of your brain can affect your vision, leading to blurred vision. In this case, your eyes and vision are fine, but the blurred vision occur as a result of nerve damage.
Also, a pinched nerve in the neck can trigger pain around the eyes, which is named greater occipital neuralgia academically.
Yes, your pinched nerve will cause blurred vision because the neck nerves are interlinked with eye nerves. You'd better find some medical way to treat your neck problems. About your blurred vision, you could use some eye drops to release the symptom and make the eyes get moisture and comfortable. In addition, you could use the warm compress to make your eyes see clearly.
Well, generally speaking, it is very normal to have blurry vision when you suffer a pinched nerve. And that is from doctor. According to some experts, it may be because the neck nerves are interlinked with eye nerves. In that way, it will just affect your eyes, leading to some eye problems when pinched nerve in neck occurs. To solve the problem, the first thing you should do is to try some medical ways to treat your neck problems. And for blurry vision, I have to say that it is kind of dangerous when you have driving or walking outside. So just have some eye drops to release the symptom and make the eyes get moisture and comfortable. By the way, warm compress can be used, so that it will be effective.
I'm sorry but I really can't make an anatomical connection between pinched nerve in neck and vision problems. They're not really related. Believe me, there are thousands of problems of the eye itself to cause blurred vision that it doesn't need to have anything to do with neck. Obviously, you are not feeling well and at those times, your sense of vision will suffer, just as you won't want to be around loud noises or do extremely difficult mental work. Medication side effects could be playing a role - I wonder if you are on pain meds for back/neck. Muscle relaxors and narcotics are especially bothersome for vision. As you have been hurting and in pain, it sounds like your ciliary muscles could be weakening and you refraction went from +150 to +350 so that also fits the picture. Anyway keep in contact with good board-certified ophthalmologist and try to find the ways that the two problems (neck and eyes) are not necessarily physically related yet linked also in other ways.