It was difficult to see and walking was a challenge / vision seemed still not right; Floater went away but I still felt strange and vision seemed still not right.; Then got a low grade headache / still have it writingthis; Following booster waiting the 15 minutes after the shot "I" felt head rush; Then saw a medium sized eye floater / saw a small eye floater appear / It grew to take on the whole of my vision / Inside the floater was really sharp and bright/ Outside was sort of diminished and a little dark and faded / Floater went away; The patient received the third/booster dose of BNT162b2; This is a spontaneous report from a contactable consumer, the patient. A 56-year-old male patient received the third (BOOSTER) dose of BNT162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Lot Number: FG3527) via an unspecified route of administration in the left arm on 03Nov2021 at 19:00 (at the age of 56-years-old) as a single dose for COVID-19 immunisation. Medical history was reported as no current and chronic conditions. The patient had no known allergies. Prior to the vaccination, the patient was not diagnosed with COVID-19. The patient did not receive other vaccines within four weeks prior to the vaccination. Concomitant medications included citalopram (MANUFACTURER UNKNOWN) for an unknown indication from an unknown date and unknown if ongoing. The patient previously received the first dose of BNT162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Lot Number: EL3247) via an unspecified route of administration in the right arm on 22Mar2021 at 10:00 (at the age of 56-years-old) and also received the second dose of BNT162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Lot Number: EP6955) via an unspecified route of administration in the right arm on 12Apr2021 at 10:00 (at the age of 56-years-old) as a single dose for COVID-19 immunisation. On 03Nov2021 at 19:15, while waiting for 15 minutes following booster dose, the patient felt head rush, then saw a medium sized eye floater. It was unusual and so the patient reported it to the pharmacy who said that they had never heard of this side effect. The event passed, so the patient dismissed it. On 12Nov2021, the patient experienced a similar sensation and saw a small eye floater appear. It grew to take on the whole of his vision. Inside the floater was really sharp and bright, outside was sort of diminished and a little dark and faded. It was difficult to see and walking was a challenge. The patient removed his contacts and drank a lot of water. Floater went away but he still felt strange and vision seemed still not right. Then he got a low-grade headache and still had it while writing this report. The events did not result in doctor or other health care professional office/clinic visit, and emergency room/department or urgent care. Therapeutic measures were not taken as a result of the events. Since the vaccination, the patient had been tested for COVID-19. On 02Nov2021, the patient underwent SARS-COV-2 test (spit test; required weekly at the patient's work) and the result was negative. The clinical outcome of the event medium sized eye floater, similar sensation and saw a small eye floater appear, grew to take on the whole of his vision, inside the floater was really sharp and bright, outside was sort of diminished and a little dark and faded was resolved on 12Nov2021; felt head rush, difficult to see and walking was a challenge, felt strange and vision seemed still not right and low-grade headache were unknown at the time of this report.