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 detected during an examination of the back of the eye, because the retinal vessels react and change relatively early in response to high blood pressure.
The diagnosis is then called "Fundus hypertonicus". Fundus hypertonicus refers to damage to the arterial vessels (arterioles) of the retina caused by high blood pressure. Due to vasoconstriction - the narrowing of the vessels in response to excessively high blood pressure - the typical changes associated with fundus hypertonicus appear as narrowed, thin vessels. In advanced stages, Gunn's signs can be seen. These describe compression of the crossing veins at the points where they cross the 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 vessels with focal narrowings, positive Gunn sign |
| III | additionally, hemorrhages, hard exudates, and cotton-wool spots |
| IV | additionally, optic disc edema and optic atrophy |
The vessels can also become blocked, become more twisted, or form small outpouchings. This damage to the vessels reduces 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 retinal detachment.
There are no noticeable symptoms in the early stages. As the disease progresses, visual acuity decreases and visual field loss occurs.
There are no noticeable symptoms in the early stages. As the disease progresses, visual acuity decreases and visual field loss occurs.
If there is severe damage, venous congestion can cause swelling of the optic nerve-a condition known as papilledema. Visual problems up to and including blindness can result from high blood pressure.
If these high-blood-pressure-related visual problems occur suddenly (for example during a hypertensive crisis), they are often reversible. However, 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. However, 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
Blood pressure that is too low at night can also affect the eye. The inadequate blood supply to the eye that may result has been identified as a risk factor for developing glaucoma, also known as "green star." However, this does not only affect people whose blood pressure is generally low; it can also occur in patients with high blood pressure whose blood pressure drops too far 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 is from Tensana – the leading app since 2011, helping hundreds of thousands of people 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 outpatient care, and has headed the specialist editorial team at Tensana since 2015. Thanks to her extensive additional qualifications as an emergency medical technician, first responder, and in various areas of therapy and emergency care, she provides well-founded, practical, and reliably verified information.
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as outpatient care, and has headed the specialist editorial team at Tensana since 2015. Thanks to her extensive additional qualifications as an emergency medical technician, first responder, and in various areas of therapy and emergency care, she provides well-founded, practical, and reliably verified information.
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