PLATELET COUNT INCREASED; EXCRUCIATING HEADACHE; INTRAOCULAR PRESSURE DECREASED; ANGIOGRAM NORMAL; ARTERIOGRAM CAROTID NORMAL; THROMBOCYTOPENIA; ARTERY BURST BEHIND HER EYE; OCULAR DISCOMFORT; PERIORBITAL SWELLING; EYE PAIN; ACHES AND PAINS; This spontaneous report received from a patient concerned a 61 year old female, ethnicity unknown. The patient's height, and weight were not reported. The patient's past medical history included hypertension, hypothyroidism, and intermittent pancytopenia, and concurrent conditions included metronidazole allergy, hashimoto's disease, and microscopic colitis. The patient was previously treated with metronidazole.  The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, intramuscular, batch number: 1805018, and expiry: UNKNOWN) dose was not reported, administered on 09-MAR-2021 for prophylactic vaccination. Concomitant medications included amlodipine, levothyroxine, losartan, rosuvastatin calcium, and ubidecarenone.  On 09-Mar-2021, the patient got the vaccine and after few days she had aches and pains (very mild reaction) and went to bed early. The patient thought she was fine. On 18-Mar-2021, 04:00, she woke up with an excruciating headache above her left eye in her eyebrow. The patient wondered if it was an aneurysm and took 2 tablets of extra strength Tylenol and it helped. The patient stated that after every 5-6 hours, excruciating headache came back. The patient had the same headache for over a week. The patient got tested for Covid-19 and it was negative. The patient thought she had sinus problems but had no other symptoms. On 30-Mar-2021, the patient woke up with headache. Her eye was killing her, was sore and swollen, and felt like it was going to burst and her left eye was swollen shut in a couple of hours. The patient narrated it was excruciatingly painful. The patient's husband drove her to urgent care, where ophthalmology tested the pressure: right eye was normal (she thinks it was 18- normal) and the left eye was 51 (normal is 14-19), units unspecified (intraocular pressure decreased). The eye doctor started prednisone and the patient had a CT scan and lab work done. MRI was also ordered but they were unable to do it right away. On unspecified date in Dec/2020 the platelets were 349 in December and came down to 64, which was very low (low threshold was 150) (thrombocytopenia). The CT scan was performed, they thought she had a cavernous carotid fistula and she was scheduled for an angiogram for a further diagnosis on 01-Apr-2021. The angiogram determined she did not have fistula. The patient was admitted to the hospital after the angiogram and on 02-April-2021, MRI was done. All throughout the process, the ophthalmologist, radiologist and internist all thought it was related to the Janssen COVID-19 vaccine. The prednisone started working and the pressure started dropping in her eye. The patient states that doctors think an artery burst behind her eye. After discharge, the patient was taking prednisone which was helping. On the 13th, she was watching television and saw that the vaccine was being put on hold due to the women with clots whose progression matched hers exactly (severe headaches, low platelets, and required attention). She was on prednisone for a month. Laboratory data (dates unspecified) included: COVID-19 virus test negative (NR: not provided) negative, CT scan (NR: not provided) Not reported, and Platelet count (NR: not provided) 64 (units unspecified). Treatment medications (dates unspecified) included: prednisone, and paracetamol. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from thrombocytopenia, intraocular pressure decreased, ocular discomfort, periorbital swelling, and eye pain, excruciating headache on 02-APR-2021, and aches and pains on 12-MAR-2021, and the outcome of artery burst behind her eye was not reported. This report was serious (Hospitalization Caused / Prolonged, and Disability or Permanent Damage).  Additional information was received on 25-MAY-2021 following information was updated and incorporated into case narrative: Other identification number, patient contact details, events- Aches and pains, artery burst behind her eyes, excruciating headache, Tylenol drug was added, hospital details was added and narrative was updated accordingly.; Sender's Comments: V1: Additional information updated identification number,hospital details,events- Aches and pains, artery burst behind her eyes, excruciating headache,This updated information does not change the causality of previously reported events. 20210502268-COVID-19 VACCINE AD26.COV2.S-Artery burst behind her eye. Follow-up received regarding Clinical Details. This event(s) is considered not related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event(s) than the drug. Specifically: MEDICAL HISTORY 20210502268-COVID-19 VACCINE AD26.COV2.S-Excruciating headache. Follow-up received regarding Clinical Details. This event(s) is labeled per RSI and is therefore considered potentially related. 20210502268-covid-19 vaccine ad26.cov2.s-Thrombocytopenia, Intraocular pressure decreased, Ocular discomfort, Periorbital swelling, Platelet count increased, Eye pain, Angiogram normal, Arteriogram carotid normal. This event(s) is considered not related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event(s) than the drug. Specifically: MEDICAL HISTORY, UNDERLYING DISEASE