High blood pressure and its effects on the eyes
High blood pressure affects blood vessels throughout the body. The vessels in the eyes are especially affected.
Elevated blood pressure is often first noticed during an examination of the back of the eye, because the retinal vessels tend to react and change relatively early in response to high blood pressure.
The diagnosis is then called "Fundus hypertonicus". As Fundus hypertonicus we refer to damage to the arterial vessels (arterioles) of the retina caused by high blood pressure. The typical changes of a Fundus hypertonicus appear as narrowed, thin vessels due to vasoconstriction the vessels constricting in response to high blood pressure. In advanced stages, Gunn's signs can be seen. These describe a compression of the crossing veins at the points where they cross hardened, narrowed arterioles.
Fundus hypertonicus is divided into four stages; from stage three it is also called hypertensive retinopathy.
Depending on the stage, the vessels appear functionally altered, markedly changed, and later as so-called "copper wiring" and in the final stage as "silver wiring." These terms come from different light reflex phenomena that indicate the degree of change in the vessels.
Depending on the stage, the vessels appear functionally altered, markedly changed, and later as so-called "copper wiring" and in the final stage as "silver wiring." These terms come from different light reflex phenomena that indicate the degree of change in the vessels.
| Stage |
Findings |
| I | mild, generalized narrowing of the arterioles, noticeable tortuosity (twisting), no focal narrowings |
| II | marked, generalized narrowing of the retinal vessels with focal narrowings, positive Gunn sign |
| III | additionally bleeding, hard exudates, and cotton-wool spots |
| IV | additionally optic disc swelling (papilledema) and optic nerve atrophy |
The vessels can also become blocked, become more twisted, or form small outpouchings. These vessel damages reduce the supply of nutrients to the nerve cells. Deposits and bleeding can form on the retina. Ultimately, the nerve fibers of the retina can die. This can lead to a retinal detachment.
In earlier stages there are usually no symptoms. As the disease progresses, visual sharpness decreases and visual field defects can occur.
In earlier stages there are usually no symptoms. As the disease progresses, visual sharpness decreases and visual field defects can occur.
If there is severe damage, venous congestion can cause swelling of the optic nerve a so-called papilledema. Visual problems up to and including blindness can be a consequence of high blood pressure.
If these high-blood-pressure-related visual problems occur suddenly (for example during a hypertensive crisis), they are often reversible. But if blood pressure is chronically high, the changes in the eyes can also become chronic and vision can continue to worsen.
If these high-blood-pressure-related visual problems occur suddenly (for example during a hypertensive crisis), they are often reversible. But if blood pressure is chronically high, the changes in the eyes can also become chronic and vision can continue to worsen.
A tip for people with high blood pressure who need new glasses:
Have your new glasses fitted only after your blood pressure is well controlled with medication. Some blood pressure medicines can affect vision (as can other drugs, for example painkillers). This varies from person to person. Changing or adjusting medications can also cause increased tiredness, which can in turn affect vision. For this reason, opticians recommend fitting new corrective lenses only once medication is stable.
Low blood pressure as a risk factor for glaucoma
Too low a blood pressure at night can also affect the eye. The resulting reduced blood supply to the eye has been identified as a risk factor for developing glaucoma. This does not only affect people whose blood pressure is generally low, but can also occur in patients with high blood pressure whose blood pressure drops too much at night.
Sources:
- https://www.blickcheck.de/auge/krankheiten-und-sehstoerungen/krankheiten-mit-auswirkungen-auf-die-augen/bluthochdruck/
- http://www.apotheken-umschau.de/Augen/Netzhauterkrankung-bei-Bluthochdruck-Hypertensive-Retinopathie-Diagnose--78417_4.html
- https://www.msdmanuals.com/de-de/heim/augenkrankheiten/erkrankungen-der-netzhaut/retinopathie-durch-hohen-blutdruck
- https://flexikon.doccheck.com/de/Fundus_hypertonicus
- https://www.uniklinikum-dresden.de/de/das-klinikum/kliniken-polikliniken-institute/augenheilkunde/leistungsspektrum/spezialsprechstunden/glaukomdiagnostik
This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands monitor their blood pressure every day.
Our content is based on carefully researched, evidence-based data and is continuously updated (as of 11/2025).
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.
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