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New research: drinking coffee wrong, too much fear harms eyesight

Published: 2026-08-17 Author: World Gafei

Last Updated: 2026/08/17, Communication of professional baristas Please pay attention to the coffee workshop (Wechat official account cafe_style) if you drink coffee wrong, too much coffee may cause harm to your eyesight. Many office workers are used to having a cup of coffee when they work overtime, but medical research points out that those who are used to drinking two or three cups of coffee a day, or even stay up late after 10:00 in the evening, their intraocular pressure (IOP) will soar twice as much as usual, even reaching Qingguang.

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Drinking the wrong coffee, too much may cause damage to eyesight. Information photos of this newspaper

Many office workers are used to having a cup of coffee when they work overtime, but medical research has pointed out that those who drink two or three cups of coffee a day, or even stay up late to drink coffee after 10:00 in the evening, their intraocular pressure will soar twice as much as usual, even reaching the standard of glaucoma. If this is the case for a long time, it will cause irreparable damage to eyesight.

Department of Ophthalmology, Tokyo Medical University, Japan, conducted four group experiments on 320 volunteers who consumed different amounts of caffeine (150mg to 450mg, about 1 to 3 cups) at different times (150mg to 450mg, about 1 to 3 cups) and found that those who drank three cups of coffee after 10:00 in the evening had the highest intraocular pressure (36.6mmHg) (mm Hg). He warned that if drinking a large amount of coffee every day for a long time exceeds 500mg, the intraocular pressure will be on the high side for a long time, which will have a serious impact on vision.

Volunteers aged 28 to 33 who did not suffer from chronic diseases or glaucoma were divided into four groups: drinking a cup of coffee during the day and drinking 1, 2 and 3 cups of coffee respectively after 10:00 at night. The changes of intraocular pressure (IOP) were measured before and after drinking coffee. The results showed that the IOP of those who drank one cup of coffee during the day gradually increased from 15.5 (±2.5) mmHg to 24.8 (±3.6) mmHg. The intraocular pressure (IOP) of those who drank 3 cups of coffee after 10:00 in the evening soared from 17.2 (±3.5) mmHg to 32.6 (±4.2) mmHg.

A cup of coffee on the market contains about 150 to 200 milligrams of caffeine. Hong Qiting said that the intraocular pressure of the human body at night is already higher than that during the day. If office workers stay up late for a long time and drink a lot of coffee to refresh themselves, it will take at least 2 to 10 hours for caffeine to be metabolized out of the body gradually, and the intraocular pressure is in a state of high standard for a long time, which can easily cause optic nerve injury, cause visual field defect, and further form glaucoma.

Hong Qiting said that several young OL were found in the clinic who did not leave their coffee every day and had long-term headaches, eye distension, heart palpitations and high intraocular pressure. He said that coffee people should drink no more than four cups of coffee a day, and try not to drink a lot of coffee when staying up late, so as to reduce the chance of soaring intraocular pressure.

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