{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T16:03:04Z","timestamp":1792080184095,"version":"4.4.0"},"reference-count":61,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2024,10,25]],"date-time":"2024-10-25T00:00:00Z","timestamp":1729814400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Ophthalmic Physiologic Optic"],"published-print":{"date-parts":[[2025,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>Smartphones are the most frequently used digital devices globally with ~6.80 billion users. Despite the ubiquitous use of smartphones, limited information is known on the preferred viewing distance and font size of smartphone users. This study investigated viewing distance, font size\u00a0and symptoms of eyestrain in non\u2010presbyopic and presbyopic smartphone users.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      In this quantitative research study, viewing distance and font size were measured in a group of non\u2010presbyopes (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u2009107) and presbyopes (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u200953), whilst participants viewed a text message and a web page on their own smartphone. Subjects also responded to a verbal questionnaire related to the characteristics of their smartphone and the computer vision syndrome questionnaire to assess symptoms of eyestrain. Data were analysed using descriptive and inferential statistics.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      For the total sample, the mean viewing distance for a text message was 37.13\u2009\u00b1\u20098.82\u2009cm (median 36.00\u2009cm), and for a web page was 36.11\u2009\u00b1\u20097.98\u2009cm (median 36.00\u2009cm). Presbyopes had longer median viewing distances compared with non\u2010presbyopes for a text message (41\u2009cm vs. 34\u2009cm,\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001) and web page (40\u2009cm vs. 34\u2009cm,\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001). The font size for non\u2010presbyopes were\u2009&lt;1.0\u2009M whilst for presbyopes were\u2009&gt;1.2\u2009M. More than twice the percentage of non\u2010presbyopes were classified with digital eyestrain (DES) compared with presbyopes.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Non\u2010presbyopes used shorter viewing distances, smaller font sizes and were more predisposed to DES than presbyopes. The viewing distances adopted by presbyopes were similar to the conventional near\u2010working distance of 40\u2009cm. Eye care practitioners should consider viewing distances when assessing near\u2010visual functions and prescribing a near refractive correction, particularly in non\u2010presbyopes. There should be greater awareness of the importance of adopting appropriate viewing distances when using smartphones.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/opo.13410","type":"journal-article","created":{"date-parts":[[2024,10,25]],"date-time":"2024-10-25T06:39:38Z","timestamp":1729838378000},"page":"269-279","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Viewing distance, font size and symptoms of eyestrain in non\u2010presbyopic and presbyopic smartphone users"],"prefix":"10.1007","volume":"45","author":[{"given":"Shivani","family":"Naipal","sequence":"first","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nqobile","family":"Khumalo","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Muhammad","family":"Rahmtoola","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sinoxolo","family":"Chagi","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luyanda","family":"Didi","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandile","family":"Mthethwa","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simmy","family":"Ndhlovu","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bhavna","family":"Persadh","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6873-5375","authenticated-orcid":false,"given":"Nishanee","family":"Rampersad","sequence":"additional","affiliation":[{"name":"Discipline of Optometry, School of Health Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2024,10,25]]},"reference":[{"key":"e_1_2_12_2_1","article-title":"Smartphone ownership and internet usage continues to climb in emerging economies","author":"Poushter J","year":"2016","journal-title":"Pew Res Center"},{"key":"e_1_2_12_3_1","doi-asserted-by":"publisher","DOI":"10.1249\/TJX.0000000000000039"},{"key":"e_1_2_12_4_1","first-page":"1909","article-title":"Smartphones, tele\u2010ophthalmology, and VISION 2020","volume":"10","author":"Mohammadpour M","year":"2017","journal-title":"Int J Ophthalmol"},{"key":"e_1_2_12_5_1","unstructured":"TaylorP.Number of smartphone users in South Africa from 2014 to 2023 (in millions).2019[cited 2023 Oct 02]. 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