State opened Covid vaccines to 50 and over on Mon, March 22. I immediately scheduled my appointment for a first shot at a Dept of Health site near me for Wed, March 24. I had no immediate negative side effects. When I woke on Fri, March 26 and commenced my day of remote work from home, I noticed my left eye vision was blurry. I proceeded to work that day and continued my normal activities into the weekend assuming my vision would self-correct. By Sunday, March 26, my left eye vision was still noticeably problematic so I scheduled to see an optometrist whom I had seen before. I saw him at 12:15pm on Tues, March 30. After running numerous vision tests, optometrist let me know my vision loss in the left eye seemed to be the result of a stroke that had cut blood flow in the optic nerve and damaged my vision in the lower portions of the left eye. The center and upper portions of my left eye were generally unaffected at that time. He suggested I see my primary care physician to check for vitals, such as blood pressure and do other blood work, and more importantly see a neuro ophthalmologist urgently.   The next morning, Wed, March 31 I saw my PCP, who informed me my blood pressure was normal, requested blood work, and gave me a prescription for an MRI of my brain, with and without contrast. I am 6'2" and I weighed at 239, about where it has been for most of last 15 years. I also complained of pain and stiffness in my front right thigh and lower right back. She said if I didn't get an appointment to see a neuro ophthalmologist that same afternoon, she recommended I go to an ER. With the help of Optometrist's office, I was able to get an appointment that day with Dr., neuro ophthalmologist at 2:15pm on Wed, March 31. His office repeated numerous vision tests and confirmed the left eye vision loss (essentially the lower half excluding the center) and diagnosed it as a NAION - non arthritic ischemic optic neuropathy. With this diagnosis, there was no treatment, and I scheduled a follow-up for May 12. He said that my optic nerve into my left eye would slowly reduce its swelling over the next 6 to 8 weeks and in that time, my vision could remain the same, or improve. At that point, I didn't think it would worsen, but sadly that later happened. In addition to the the first MRI that PCP prescribed, Neuro ophthalmologist prescribed a second MRI of orbits, with and without contrast. He also suggested I begin taking a low dose Aspirin daily, which I did.   The next week, the blood work revealed a very slightly elevated cholesterol reading. I was told by my PCP on April 5 that this would normally not be considered as a problematic level of high cholesterol, but should be improved or lowered. The blood tests taken at Lab on Fri, April 2 revealed a LDL Chol, Calculated as 111, whereby <100 was considered desirable range. Other than that, there was nothing of concern in my blood work. The two MRIs were done on April 9 and April 20, and did not reveal findings which doctors felt would have impacted my optic nerve swelling or had caused the eye stroke. Out of precaution, I scheduled to see a cardiologist on Tues, April 13. She recommended I start taking Crestor for cholesterol, and do a series of tests which I completed on Friday, April 23 - echocardiogram; holter monitor; transesophageal echocardiogram; and ultrasound carotid bilateral. As of today, Mon, April 26 I do not know the results of the cardio work-up, but both neuro ophthalmologists I saw felt that a problem related to my heart would not have caused this stroke in my eye.   Finally, on Fri, April 23 I had a consultation with a second highly recommended neuro ophthalmologist. After a series of vision tests, she agreed with other doctor's diagnosis of NAION - non arthritic ischemic optic neuropathy. She also said there was nothing I could do to treat except wait for the next 4 or more weeks for the optic nerve swelling to go down. She also confirmed my fear which was that my left eye vision had worsened since March 31 as my vision loss was no longer limited to the lower portion of my left eye, but now included blind spots throughout the upper range of my left eye vision, making my loss of peripheral vision worse and more widespread. She said in some cases with NAION, a patient's vision could remain the same, could improve or could worsen in the 6 to 8 weeks after the event. Four weeks after the March 26 event, by April 23 my left eye vision had worsened. I still hold out hope that it can improve some in the next four weeks... My right eye vision was not affected in any way, although one risk of NAION is that there is a 20% (?) chance it may recur in the next 5 years, and if it does, it most commonly affects the other, good eye.   None of the doctors I saw directly attributed my vision loss to the Moderna vaccine taken on March 24; however, there has also not been a clear cause determined by my doctors. While most of the doctors I saw seemed to think it coincidental, none also was able to absolutely rule it out either as a cause or a trigger. Dr. suggested I follow through with this idea, which other medical professionals suggested, to submit this vaccine adverse event report. Without a doubt, this was an adverse effect and/or problem that occurred soon after (36 hours approximately) taking the first dose of the Moderna vaccine.