I have to respond here too... this aching pain can come from sinus infections.

Also if your homocysteine is high, this can inflame the tiny blood vessels in the retina, and cause ischemia. This is more common than people realize. When combined with high blood pressure or stress that raises blood pressure sporatically, you can even get a blood clot in the retina....I had that over 10 yrs ago, and it does hurt..a vague aching pain.

Homocysteine is lowered by B12, B6, and folate. So if you have the MTHFR mutation, you might have elevated homocysteine due to being unable to activate B12 and folic acid to their active methyl forms.

You can search NT here for "MTHFR" and find many threads on this subject at our PN board, PD board, MS board and here too.
10% to 30% of people are thought to have this and need to supplement the active forms of B12 and folate(methylcobalamin and methylfolate).. which are both over the counter.

This will lower homocysteine and therefore protect your blood vessels.

An opthalmologist can see this damage in an exam with lenses, and if something shows up there, a further angiogram will show details.