Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 3 complete abstracts (769 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Clarity or sharpness of ocular vision or the ability of the eye to see fine details. Visual acuity depends on the functions of retina, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Acuities, Visual; Acuity, Visual; Visual Acuities.
Where it fits in the MeSH classification
- Broader topics
- Vision Tests; Visual Perception; Ocular Physiological Phenomena
- Narrower topics
- Contrast Sensitivity; Emmetropia
- See also
- Refraction, Ocular; Refractive Errors
Related concepts
- Ocular Vision
- Retina
Research landscape
PubMed indexes 105,860 records tagged with the MeSH heading “Visual Acuity” (counts retrieved 2026-10-31). 23,739 of them (22.4%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 35,155 records.
Reviews account for 5,250 records (5.0%) and meta-analyses for 933. Randomized controlled trials number 6,109 (5.8%) as a share of all records on the topic.
Show the data
| Period | Records |
|---|---|
| through 1999 | 24,573 |
| 2000-2009 | 22,393 |
| 2010-2019 | 35,155 |
| 2020 onward | 23,739 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 5,250 | 5.0% |
| Meta-analyses | 933 | 0.9% |
| Randomized controlled trials | 6,109 | 5.8% |
Method: PubMed query "Visual Acuity"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in psychiatry and psychology
Research on mental health and behaviour relies on questionnaires, interviews and rating scales rather than physical measurements, so how a condition was defined and measured shapes every result. Many studies are observational or small, placebo responses can be large, and findings in one group or culture may not carry over to another. Nothing on this page is advice about diagnosis or treatment; anyone worried about their mental health should talk to a qualified clinician. Check how outcomes were measured, who took part and how long they were followed.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| The Impact of Myopia Control Spectacle Lens Designs on Visual Function | 2026 | Randomized controlled trial Design not recorded in structured metadata | 3 | cc by PMID 41784766 · DOI · PMC13369762 |
| Real-world treatment patterns and visual outcomes of faricimab in patients with neovascular age-related macular degeneration in the UK at 12 months: the FARWIDE-nAMD study | 2026 | Research article Design not recorded in structured metadata | 2 | cc by PMID 41807615 · DOI · PMC13194951 |
| The Effect of Limbal Fenestrations on Scleral Lens-Induced Central Corneal Oedema | 2026 | Research article Design not recorded in structured metadata | 2 | cc by PMID 41803503 · DOI · PMC13368883 |
The Impact of Myopia Control Spectacle Lens Designs on Visual Function [1]
Abstract reading summary — source excerpts
- Opening excerpt
- PurposeTo profile the immediate effect of defocus-modulating and contrast-modulating myopia control spectacle lens interventions on visual function.
- Closing excerpt
- Clinicians should note differences in visual performance, especially VA and reading speed through the lens periphery and their relative testing.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (232 words)
PurposeTo profile the immediate effect of defocus-modulating and contrast-modulating myopia control spectacle lens interventions on visual function.MethodsHealthy myopic (mean spherical equivalent (MSE) -4.25 to -0.50 D) young adults, corrected with contact lenses, wore diffusion optics technology (DOT), defocus incorporated multiple segments (DIMS), highly aspherical lenslets (HAL) and standard single vision (SV) plano trial spectacle lenses, in a prospective, single-visit, double-blind, four-way randomised crossover study. Distance and near high- and low-contrast visual acuity (VA), contrast sensitivity, reading performance, accommodative facility, visual search task and accommodative accuracy were assessed foveally through the central zone (CZ) and/or peripheral zone (PZ) of the lenses.ResultsTwenty participants (16 female) were recruited, with a mean (±SD) age of 22.4 (±2.72) years and MSE -2.21 (±1.10) D. VAs through the PZ differed significantly between myopia control lenses and SV, with the HAL and DIMS exhibiting lower VA across all testing conditions (all p 0.05), whereas DIMS exhibited worse near acuity threshold and critical print size (p 0.05) or visual search duration (CZ: p = 0.68; PZ: p = 0.35). Accommodative response was similar across lenses (all p >0.05); however, SV had lower variability at distance through the PZ than DOT, HAL and DIMS (p ConclusionAll three myopia control lenses exhibited visual performance comparable to standard SV lenses through the CZ. Clinicians should note differences in visual performance, especially VA and reading speed through the lens periphery and their relative testing.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41784766 · DOI · PMC13369762
Real-world treatment patterns and visual outcomes of faricimab in patients with neovascular age-related macular degeneration in the UK at 12 months: the FARWIDE-nAMD study [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe Faricimab Real-World Evidence (FARWIDE) studies are evaluating real-world outcomes of eyes with neovascular age-related macular degeneration (nAMD) or diabetic macular oedema (DMO) treated with faricimab in the UK.
- Closing excerpt
- ConclusionsThese 1-year data support real-world faricimab effectiveness, durability, and safety in nAMD.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (242 words)
BackgroundThe Faricimab Real-World Evidence (FARWIDE) studies are evaluating real-world outcomes of eyes with neovascular age-related macular degeneration (nAMD) or diabetic macular oedema (DMO) treated with faricimab in the UK. Here, we present results from FARWIDE-nAMD for eyes with 12 months of follow-up after faricimab initiation.MethodsnAMD patient-eyes that received ≥1 faricimab injection after May 2022 at one of 35 participating UK National Health Service retinal clinics with ≥12 months of follow-up after faricimab initiation as of July 2024 were included. Treatment-naïve (TN) eyes had no prior anti-VEGF treatment. Previously treated (PT) eyes switched from an anti-VEGF to faricimab. Baseline characteristics, VA, and injection frequency were assessed. Intraocular inflammation (IOI) and presumed infectious endophthalmitis (PIE) rates were pooled for nAMD and DMO eyes with any follow-up duration on faricimab. Analyses are descriptive.Results5854 nAMD patients (6991 eyes; 26.5% TN, 73.5% PT) were included. 83.3% of PT eyes switched from aflibercept 2.0 mg. TN eyes received a mean (SD) of 4.7 (0.7) faricimab injections in months 1-6 and 2.2 (1.1) injections in months 7-12. PT eyes received 4.5 (1.0) injections in months 1-6 and 3.0 (1.2) in months 7-12. In TN eyes, mean (SD) VA increased from 56.4 (16.3) Early Treatment Diabetic Retinopathy Study letters at baseline to 60.1 (19.4) at 12 months (mean [SD] change 3.6 [14.7] letters). PT eyes had stable VA. IOI and PIE rates were consistent with faricimab phase 3 trials.ConclusionsThese 1-year data support real-world faricimab effectiveness, durability, and safety in nAMD.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41807615 · DOI · PMC13194951
The Effect of Limbal Fenestrations on Scleral Lens-Induced Central Corneal Oedema [3]
Abstract reading summary — source excerpts
- Opening excerpt
- PurposePersistent corneal oedema can lead to reduced visual performance and longer-term ocular complications in eyes with reduced endothelial cell function.
- Closing excerpt
- Clinical trialThis study was registered on the Australian New Zealand Clinical Trials Registry (Registration number 12622001164785p), date of registration 24 August, 2022.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (295 words)
PurposePersistent corneal oedema can lead to reduced visual performance and longer-term ocular complications in eyes with reduced endothelial cell function. The aim of this study was to quantify the effect of incorporating limbal scleral lens fenestrations on central corneal oedema.MethodsTwenty young healthy adults (mean age ± standard deviation 32 ± 11 years) with normal corneas wore non-fenestrated and fenestrated (3 × 1 mm limbal fenestrations separated by 120°) OneFitMed+ scleral lenses in both eyes (on separate days) for 3 h. All other scleral lens parameters were held constant except for the addition of the fenestrations. Central fluid reservoir thickness and corneal oedema were quantified using optical coherence tomography, and corrections were made for small thickness variations between lens conditions.ResultsThe corrected central corneal oedema was significantly reduced following fenestrated lens wear (0.80 ± 0.93%) compared to non-fenestrated lens wear (1.32 ± 0.81%; a 39% relative reduction, p = 0.02). The reduction in central corneal oedema with the fenestrated lens was slightly greater for participants without an air bubble in the fluid reservoir (n = 10, 0.73 ± 0.80% less oedema, 45% relative reduction) compared to those with an air bubble (n = 10, 0.30 ± 1.05% less oedema, 30% relative reduction) but was not statistically significant (p = 0.31).ConclusionThe incorporation of three 1 mm diameter limbal fenestrations separated by 120° reduced the magnitude of central corneal oedema by 39% on average in healthy eyes compared to a non-fenestrated scleral lens. A reduction in central corneal oedema was still observed without the presence of an air bubble within the fluid reservoir. Future studies investigating the long-term efficacy of different fenestration configurations in clinical populations are warranted.Clinical trialThis study was registered on the Australian New Zealand Clinical Trials Registry (Registration number 12622001164785p), date of registration 24 August, 2022.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41803503 · DOI · PMC13368883
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study [4]
- Research article Trends in prevalence of blindness and distance and near vision impairment over 30 years: an analysis for the Global Burden of Disease Study [5]
- Research article The Complications of Myopia: A Review and Meta-Analysis [6]
- Research article IMI Pathologic Myopia [7]
- Research article Global Prevalence of Presbyopia and Vision Impairment from Uncorrected Presbyopia: Systematic Review, Meta-analysis, and Modelling [8]
- Research article Postoperative Efficacy, Predictability, Safety, and Visual Quality of Laser Corneal Refractive Surgery: A Network Meta-analysis [9]
Full-text reviews on EvidenceLib
Open-access review articles about this topic, reproduced in full with authors, licence and references.
A Systematic Review and Meta-Analyses of Interventional Clinical Trial Studies for Gene Therapies for the Inherited Retinal Degenerations (IRDs)
Gearóid P. Tuohy, Roly Megaw · Biomolecules 2021 · CC BY 4.0
References
- Desiato A, Lam HY, Anand RR, Chatha I, Logan NS, Logan NS, et al.. The Impact of Myopia Control Spectacle Lens Designs on Visual Function. . 2026. PMID 41784766 · DOI · PMC13369762
- Talks J, de Salvo G, Patel PJ, de Silva SR, Gale RP, McKibbin M, et al.. Real-world treatment patterns and visual outcomes of faricimab in patients with neovascular age-related macular degeneration in the UK at 12 months: the FARWIDE-nAMD study. . 2026. PMID 41807615 · DOI · PMC13194951
- Fisher D, Alonso-Caneiro D, Vincent SJ. The Effect of Limbal Fenestrations on Scleral Lens-Induced Central Corneal Oedema. . 2026. PMID 41803503 · DOI · PMC13368883
- GBD 2019 Blindness and Vision Impairment Collaborators, Vision Loss Expert Group of the Global Burden of Disease Study. Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study. Lancet Glob Health. 2021. PMID 33275949 · DOI · PMC7820391
- GBD 2019 Blindness and Vision Impairment Collaborators, Vision Loss Expert Group of the Global Burden of Disease Study. Trends in prevalence of blindness and distance and near vision impairment over 30 years: an analysis for the Global Burden of Disease Study. Lancet Glob Health. 2021. PMID 33275950 · DOI · PMC7820390
- Haarman AEG, Enthoven CA, Tideman JWL, Tedja MS, Verhoeven VJM, Klaver CCW. The Complications of Myopia: A Review and Meta-Analysis. Invest Ophthalmol Vis Sci. 2020. PMID 32347918 · DOI · PMC7401976
- Ohno-Matsui K, Wu PC, Yamashiro K, Vutipongsatorn K, Fang Y, Cheung CMG, et al.. IMI Pathologic Myopia. Invest Ophthalmol Vis Sci. 2021. PMID 33909033 · DOI · PMC8083114
- Fricke TR, Tahhan N, Resnikoff S, Papas E, Burnett A, Ho SM, et al.. Global Prevalence of Presbyopia and Vision Impairment from Uncorrected Presbyopia: Systematic Review, Meta-analysis, and Modelling. Ophthalmology. 2018. PMID 29753495 · DOI
- Wen D, McAlinden C, Flitcroft I, Tu R, Wang Q, Alió J, et al.. Postoperative Efficacy, Predictability, Safety, and Visual Quality of Laser Corneal Refractive Surgery: A Network Meta-analysis. Am J Ophthalmol. 2017. PMID 28336402 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-11-04.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.