Brief Answer:
Follow the advice. Observe how you stay afterward.

Detailed Answer:

Hello,

Well, first of all, take a mild analgesic like Acetaminophen (Tylenol) and give it some time...Please don't engage in any physical activities for the time being, just take rest.

Was there any recent history of a cough / cold / flu?
Any vision-related issues?

Considering the fact that it's intermittent, next step would be a blood pressure check-up at different posture. If the blood pressure found in higher range, there may a requirement to start anti-hypertensive medications after a clinical evaluation.

If this is the first time you're noticing this then please report it to your primary also to keep him/her in the loop.

Let me know if I can assist you further. Take Care.
Regards

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