When blurry vision is not just eye strain: 5 things to know about glaucoma

SINGAPORE – When Ms Lim’s (not her real name) vision began blurring four years ago, she thought it might be eye strain caused by fatigue. Her work in a bank involves lots of screen time and e-mails.

Her general practitioner also thought she had eye strain and recommended rest and eye drops.

“The blurriness became more frequent and would last longer,” recalls the 44-year-old. “I would open my eyes and have this flash of darkness. Eventually, the blurriness could last for half an hour.”

An eye exam at a polyclinic showed nothing wrong. Still, she insisted on making an appointment with an eye specialist. Her father has glaucoma and she wondered whether she might have the same condition.

A few months later in 2021, a specialist at the Singapore National Eye Centre (SNEC) diagnosed her with glaucoma. She has since had multiple glaucoma operations to stop her from losing more of her sight.

Ms Lim is one of a growing number of younger people in Singapore who are being diagnosed with glaucoma. Doctors attribute the increase to better public education and more screening, but say it is unusual for people below age 60 to have the disease.

Glaucoma refers to a group of eye conditions that damage the optic nerve. This nerve carries visual information to the brain, and glaucoma results in progressive loss of sight.

The World Glaucoma Association says glaucoma is the second leading cause of blindness, affecting about 80 million people globally. About half of those with the disease do not know they have it, which is why the association raises awareness with an annual World Glaucoma Week. In 2026, it ran from March 8 to 14.

There are usually no discernible symptoms in the early stages, which is why people may not know they have it until they have some degree of irreversible vision loss. Doctors recommend regular eye exams for people aged 40 and older, especially if they have family history of glaucoma.

Ms Lim has lost 60 per cent of vision in her right eye and 30 per cent in her left due to glaucoma. She has problems with depth perception, which makes it hard to take the stairs. She also finds it difficult to read small text especially in dim light, despite using reading glasses.

“If you compare my earlier vision to the resolution of an ultra-high-definition TV, I now see in 16-bit pixel graphics,” she says.

Here are five things to know about glaucoma and its treatment.

1. What causes glaucoma

Fluid is produced in the front of the eye to nourish its structures. An internal drainage system allows this fluid to drain out from an area known as the angle of the eye.

When the drainage system malfunctions or gets blocked, fluid accumulates in the eye. Dr Desmond Quek, director of glaucoma services at Eagle Eye Centre, uses the analogy of liquid being unable to pass through a clogged sieve.

The fluid build-up leads to high internal eye pressure, which can damage the optic nerve, says the senior consultant eye surgeon.

“Over time, nerve fibres are lost, leading to ‘blind spots’ which typically affect peripheral vision first,” he adds.

Dr Quek says glaucoma may also develop in people with normal eye pressure in the range of 10 to 21mmHg. Such people have a sensitive optic nerve that cannot tolerate pressure even in this range.

He adds that glaucoma is classified according to whether the onset is acute (sudden) or chronic; whether it is primary or secondary (arising due to underlying conditions or disease or other factors); and by the nature of the malfunction (open versus closed).

Dr Yap Zhu Li, senior consultant at SNEC’s glaucoma department, says the most common form of the disease worldwide is open-angle glaucoma, where the drainage system looks open, but is microscopically clogged or damaged.

In closed-angle glaucoma or angle-closure glaucoma, the drainage system is visibly blocked. “This is quite common in Asians and, in some cases, can be acute and painful,” says Dr Yap. She is also clinical director of SNEC’s complex anterior segment service, which offers specialised eye surgery.

She says glaucoma affects about 3 per cent of people over age 50 in Singapore. This is comparable with global data.

However, she adds: “Singaporeans are at higher risk of developing angle-closure glaucoma than the global population and have one of the highest incidences of acute angle closure in the world.”

Dr Quek says the anatomy of the Asian eye is responsible for this, and it is important to get eye checks that include angle assessment.

2. Glaucoma numbers are on the rise

The risk of having glaucoma increases with age, and it affects roughly 10 per cent of people in Singapore aged 70 and above.

Doctors expect to see more cases with an ageing population worldwide.

Dr Yap says: “As populations age, numbers are expected to rise. The number of people with glaucoma globally is projected to increase to a staggering 111.8 million by 2040, with the majority of afflicted patients residing in Asia.”

Eagle Eye Centre saw 800 new glaucoma patients in 2025, and more than 6,000 visits by glaucoma patients in total.

SNEC saw between 35,000 and 40,000 glaucoma patients in 2025, with many making multiple visits.

Apart from age, risk factors for the disease include having family history of it; eye trauma; high myopia; and underlying eye conditions such as a type of inflammation called uveitis.

Diabetes, obstructive sleep apnoea and long-term use of steroids increase the risk of developing glaucoma.

At SNEC, the number of glaucoma operations performed on patients aged 40 to 49 rose from 22 in 2015 to 60 in 2025, while procedures performed on those aged 50 to 59 surged from 95 in 2015 to 183 in 2025.

Dr Yap says these were mostly cases of congenital glaucoma, secondary glaucoma after trauma, glaucoma due to poorly controlled diabetes, glaucoma after corneal grafts or retinal detachment surgery, or angle-closure glaucoma.

3. Regular eye exams are key

Dr Yap and Dr Quek say they are seeing more patients younger than 60.

Most common types of glaucoma do not present with symptoms in the early stages, doctors say.

An exception is acute angle-closure glaucoma, where patients experience sudden and severe eye pain, redness, blurred vision, headaches, and see halos around lights. They may feel nauseous or vomit.

Dr Yap refers to this as an “ocular emergency” and says such patients need urgent care.

However, doctors consider glaucoma a “silent thief of sight”, she adds, since it is asymptomatic in the early and moderate stages.

By the time blurry eyesight alerts patients, usually through loss of peripheral vision, some irreversible loss of vision has occurred.

“There’s no guaranteed way to prevent glaucoma, but early detection and monitoring can protect vision,” says Dr Yap. “Regular comprehensive eye exams are key.”

She says people over age 40, or those with risk factors, should consult their doctor on how often they should get eye exams.

Older people too often attribute vision problems to ageing or cataracts and overlook getting tested for glaucoma, she adds.

People with high myopia or those who have had Lasik may need to be more alert as doctors say these make it more difficult to screen for glaucoma.

Dr Yap says myopia and glaucoma share structural and functional similarities.

“In highly myopic eyes, myopic macular degeneration can create ‘glaucoma-like’ damage on standard tests, while standard imaging technologies may not accurately identify true glaucoma,” she adds.

Dr Quek says Lasik surgery thins out the cornea, making it more difficult to get accurate eye pressure readings.

He adds: “Tests have natural variability, so we often need repeat testing over time to be sure of the diagnosis.”

4. Treatments are eye drops and surgery

Dr Yap says treatment for glaucoma aims to lower eye pressure to prevent nerve damage. This can include eye drops or other medications to reduce fluid production in the eye or improve drainage.

However, she adds, many patients say using eye drops is more difficult than taking oral medications, which leads to issues with compliance.

Eye drops for chronic glaucoma may have side effects such as dry eyes, irritation, redness and skin changes.

Another option is laser treatments that can enhance the eye’s drainage system.

If eye drops and laser treatments are insufficient, patients may undergo trabeculectomy surgery to create new drainage pathways, or they may receive drainage implants.

Ms Lim recalls that when she was diagnosed, she had to immediately take an oral medication that reduced her eye pressure, but made her giddy. She was unable to see clearly and had to request help from passers-by to book a ride-hailing service home.

She had to use eye drops several times a day, sometimes every two hours, and eye lubricants to deal with dryness.

She went on to have trabeculectomies in both eyes in 2022, and drainage implant surgery in 2023 and 2024.

She had to stop work for about 10 months to make time for the eye procedures and recovery. She also had to give up brisk walking, her favourite exercise, because it would raise her eye pressure.

“My journey was quite traumatic,” she says.

5. Managing vision loss

Ms Lim now manages her condition with eye drops and is able to work and read using reading glasses. She is back to brisk walking, though she takes the stairs with caution as her depth perception has been affected by glaucoma.

“Taking the stairs is tough because I don’t know how deep the steps are,” she says. “People don’t understand what it means to lose your eyesight and sense of spatial recognition.”

What also helped was seeing mental health professionals. This was on the advice of her doctor, Dr Yap, as the long treatment journey left her in discomfort, anxious and unable to sleep.

Ms Lim went for therapy and had regular check-ins with a GP who kept tabs on her physical and mental well-being.

“Their help was invaluable,” she says. “It was good to have people I could speak to about my deepest fears.”

While her family was supportive, she did not want to burden her parents with her worries.

Dr Yap says there are no well-established community support groups for glaucoma, but SNEC has a low-vision service to help patients with vision loss. It can recommend optical aids and suggest adaptation strategies.

Dr Quek recommends a similar service at the Singapore Association of the Visually Handicapped, which works to enhance functional vision and improve independence.

Dr Yap says having support groups for glaucoma is something that should be further explored. “Having patients and caregivers share experiences and coping strategies would be valuable for mental and emotional well-being.”