Sight loss statistics: glaucoma certificates rose over 16 years

More than 90% of people in the world with vision impairment have a cause that could have been prevented or treated, the Lancet Global Health Commission on Global Eye Health found, and treatments for cataract and refractive error would meet more than 90% of the unmet need. England keeps its own sight loss statistics, and a study published in Eye on 16 September has counted 16 years of them. Certificates of vision impairment for glaucoma rose from 1,648 in 2009/10 to 2,645 in 2024/25. Those for diabetic eye disease fell from 1,261 to 872.

Diabetic eye disease has a national screening programme in England. Glaucoma has none: the UK National Screening Committee does not currently recommend screening for it. And glaucoma is mostly asymptomatic until late, which is why, in most prevalence surveys from high-income countries, less than half of the glaucoma found had been diagnosed before. In the week of World Sight Day, on 8 October, that is a gap a UK sight test is placed to close.

What the study counted

A Certificate of Vision Impairment (CVI) can be given to someone in England who meets the criteria for sight impairment or severe sight impairment. It records the main cause and can help them reach support. With consent, a copy of every one goes to the Royal College of Ophthalmologists' Certification Office at Moorfields Eye Hospital.

A Moorfields and UCL team counted the certificates received each year from April 2009 to March 2025, in total and for four main causes: age-related macular degeneration (AMD), glaucoma, diabetic eye disease and hereditary eye disease. It is a one-page descriptive report. The same certificates are England's measure of preventable sight loss: the Public Health Outcomes Framework reports them for AMD, glaucoma and diabetic eye disease.

What the sight loss statistics show

Certificates rose from 22,687 in 2009/10 to 24,819 in 2023/24, with a dip to 16,499 in 2020/21, the year of the COVID-19 lockdowns. The paper gives no total for 2024/25.

AMD is still the largest cause, but its share fell, from 10,393 certificates (45.8%) in 2009/10 to 9,833 (39.6%) in 2024/25. This week's other article, on how AMD is forecast to grow to 2050, is on our news page.

Glaucoma went the other way, from 1,648 certificates (7.3%) to 2,645 (10.7%), and the paper's figure shows most of that rise after the 2020/21 dip. Diabetic eye disease fell from 1,261 (5.6%) to 872 (3.5%), the biggest proportionate fall of the four. Hereditary eye disease rose from 1,077 (4.7%) to 1,652 (6.7%), and has outnumbered diabetic eye disease every year since 2010/11.

The authors do not give a reason for the rise in glaucoma. Of diabetic eye disease they write that the fall "might reflect effective screening pathways and more efficacious treatments for diabetes and diabetic retinopathy".

Avoidable sight loss, worldwide and here

The Commission's figures for 2020 are 596 million people with distance vision impairment worldwide, of whom 43 million were blind, with cataract the leading cause of blindness at 17.01 million. Refractive error is not solved in high-income countries either: effective refractive error coverage, the share of adults aged 50 and over who need distance correction and see well with it, was 84.0% in high-income countries in 2023, against 63.0% worldwide, both age-standardised modelled estimates.

Why it matters in practice

• Look at the disc and record what you saw, including for the patient who came in for new glasses. Glaucoma has no national screening programme, and it is mostly asymptomatic until late.
• By the time glaucoma reaches a certificate, the sight it has taken does not come back. The certificates cannot show how many of the 2,645 were found late, and the count rose over 16 years, most of it after 2020/21.
• When a patient's sight has fallen to certification level and nobody has mentioned a CVI, ask the hospital. In one tertiary hospital cohort with diabetic retinopathy, 84% of those with vision impairment, by acuity, had no certificate after a mean follow-up of under two years.
• Keep refraction in view. Effective coverage of 84.0% in high-income countries means about one in six adults over 50 who need distance correction still lack correction that gives them good vision.

The caveats

• The counts depend on a certificate being offered and on consent, and the authors say they do not represent the full burden of visual impairment. Under-certification, as in the UK hospital study of diabetic retinopathy, could mean national figures understate sight loss.
• They are counts, not rates. The 2020 analysis of the same certificates found no statistically significant change in the glaucoma certification rate per 100,000 people aged 40 and over between 2010/11 and 2017/18, years in which the counts rose. The new report cannot say whether the risk has changed.
• The explanation for diabetic eye disease is offered by the authors as a possibility, not shown, and AMD, which is not screened for, fell too.
• The figures cover England only. The global figures are modelled estimates, for 2020 and 2023, not counts.

Sources

1. 1.Visual impairment certifications in England over 16 years: annual numbers attributable to age-related macular degeneration, glaucoma, diabetes and hereditary eye disease · Eye, 16 September 2026
2. 2.The Lancet Global Health Commission on Global Eye Health: vision beyond 2020 · The Lancet Global Health, 16 February 2021
3. 3.Effective refractive error coverage in adults: a systematic review and meta-analysis of updated estimates from population-based surveys in 76 countries modelling the path towards the 2030 global target · The Lancet Global Health, 22 May 2025
4. 4.Recent trends in vision impairment certifications in England and Wales · Eye, 14 April 2020
5. 5.Formal registration of visual impairment in people with diabetic retinopathy significantly underestimates the scale of the problem: a retrospective cohort study at a tertiary care eye hospital service in the UK · British Journal of Ophthalmology, 22 November 2023
6. 6.Screening for glaucoma: UK NSC recommendation · UK National Screening Committee
7. 7.World Sight Day 2026: an important milestone toward eye care for all · International Agency for the Prevention of Blindness, 1 July 2026