My doctor was unable to explain the cause of my concern. Please help.

Hi doctor,

I am 28 years old. I was diagnosed as type 1 diabetic at age 25. I am used to smoke, but I quit when I was diagnosed. Recently, after a stressful situation I fell off the wagon for the first time since I was diagnosed and bought a pack of cigarettes. I did not smoke the whole pack, just a few. But, I started seeing vision changes and that seems to correlate with it. There are no floaters or flashes, but I have had this constant spot in my right eye for the past month or so. It looks exactly like the imprint light can leave in your eyes after staring at the sun or a light bulb for a long time and then looking away. It has been constantly there and never fades. It feels almost like this one section of my vision is more sensitive to light. It has got progressively more prominent. It was faint at first, but now it is very obvious and distracting when I am reading or working at the computer. It does not obstruct my vision and it is just incredibly distracting me. It is in a crescent shape. It is most obvious when I am working on the computer screen and then look away to a darker background. Also, when I blink rapidly, I see it and it almost looks like a strobe light. I had a dilated eye examination this morning and the ophthalmologist told me that there were no signs of bleeding or edema in my eyes. He said the vision changes I described were not a cause for concern, but at the same time he was not able to explain why I am seeing this. It is causing me a particular concern because once it started and I smoked another cigarette, it seemed to become more prominent, brighter, and more obvious in my field of vision. That really freaked me out and caused me to throw the rest of the pack away immediately. I have had pretty decent blood sugar control and all of my A1Cs have been in the 5.5 to 6.5 range since I was diagnosed initially. I take Adderall 25 mg for ADD and NovoLog. Is this a cause for concern? I was not able to find anything related to that type of vision change on the internet. I would really like to get an idea of what causes this type of thing for peace of mind and figure out if it is worth seeing a retina specialist.