Cataracts affect 70% of people in their 60s

Light glare and reduced corrected vision are key warning signs

Younger patients on the rise amid heavy smartphone use

Personalized surgery offers definitive treatment

Cataracts become significantly more common after age 50, affecting 70% of people in their 60s and 90% of those in their 70s, making it one of the most prevalent conditions among older adults. [Getty Images Bank]
Cataracts become significantly more common after age 50, affecting 70% of people in their 60s and 90% of those in their 70s, making it one of the most prevalent conditions among older adults. [Getty Images Bank]

Park, a man in his mid-50s, had a frightening experience while driving at night when the taillights of cars ahead suddenly appeared to bleed and blur together. Assuming it was presbyopia — age-related farsightedness — combined with dry eyes, he bought artificial tears, but the relief was only temporary. When he finally visited an eye clinic, he was diagnosed with cataracts.

Presbyopia typically sets in around the mid-to-late 40s. It occurs when the lens of the eye loses elasticity, reducing its ability to focus on nearby objects. The hallmark symptom is difficulty with close-up vision — small text on smartphones, books and menus becomes blurry, and looking at nearby objects can cause eye strain, headaches and dizziness. Reading glasses restore near vision.

Blurry overall vision is not a feature of simple presbyopia, which only impairs close-up focus while leaving distance vision intact. Nearsighted patients, whose focal point is already set for close range, can see nearby objects clearly without glasses but struggle with near vision while wearing them. Cataracts, by contrast, can cause light glare and a reduction in corrected vision — symptoms that tend to worsen at night. Anyone experiencing these signs should get a cataract examination at an eye clinic. In the early stages, cataracts gradually reduce distance corrected vision, producing a persistent hazy or foggy appearance. Temporary blurring can also occur with dry eye syndrome caused by an unstable tear film.

Cataracts become significantly more common after age 50, affecting 70% of people in their 60s and 90% of those in their 70s, making it one of the most prevalent conditions among older adults. In the early stages, corrected vision declines gradually and a persistent fog-like haziness develops. In nuclear cataracts, where the lens hardens, people who previously needed reading glasses for close work may suddenly find they can read without them — a change that should not be mistaken for an improvement in vision.

High myopia, which has surged across East Asia, is considered a leading cause of cataracts. As nearsightedness worsens, the eyeball elongates, disrupting the metabolism around the lens and making early-onset cataracts more likely. Cataracts can also develop in people who have undergone implantable collamer lens surgery or other intraocular procedures for severe myopia. Additional risk factors include metabolic syndrome in younger people linked to a Westernized diet, ultraviolet exposure from increased outdoor activity, eye rubbing caused by atopic dermatitis or allergic conjunctivitis, long-term steroid use, eye trauma and genetic predisposition.

Large-scale clinical studies in humans have not yet established a direct scientific link between cataracts and digital device use. However, excessive smartphone use — particularly at night when pupils are dilated — can increase blue light exposure over time. Laboratory research suggests blue light is absorbed by lens cells and may contribute to cataract formation. Epidemiological evidence also supports the view that the modern "digital lifestyle" is driving a rise in cataract cases among people in their 30s and 40s, with prolonged near-focus use promoting myopia, reduced blinking worsening dry eye and eye rubbing, and nighttime screen use disrupting circadian rhythms — all acting together.

Jung So-hyang, a professor of ophthalmology at Seoul St. Mary's Hospital at the Catholic University of Korea, warned that delaying treatment can allow cataracts to progress to an overripe stage, at which point the hardened lens nucleus makes surgery more time-consuming and increases the risk of complications. "As cataracts advance and the lens gradually swells, it can also block the drainage angle of the eye, triggering acute angle-closure glaucoma," she said.

Surgery is the only definitive treatment for cataracts. In the early stages, medication that slows protein degeneration can delay progression but cannot reverse it. Once the condition advances to the point of significant daily discomfort, the clouded lens is removed and an artificial intraocular lens of the appropriate power is implanted.

The timing of surgery is determined not by visual acuity scores alone but by the patient's occupation, activity level and subjective discomfort. "Younger, more active patients with high visual demands — such as those who work on computers or drive frequently — tend to opt for surgery earlier, when declining vision quality begins to interfere with daily life," Jung said. "Older patients with advanced cataracts but low activity levels, on the other hand, may choose to monitor the condition and defer surgery if they are not significantly bothered."

Cataract surgery is typically performed under topical anesthesia with eye drops. Beyond standard monofocal lenses, which correct vision at a single distance, surgeons can implant extended depth-of-focus or multifocal lenses tailored to the patient's eye, providing clear vision at multiple distances. Toric monofocal or multifocal lenses can also correct pre-existing corneal astigmatism, offering sharper vision after the procedure.

Recent advances in cataract surgery have centered on multifocal intraocular lenses capable of delivering clear vision at both near and far distances. Improved lens designs introduced each year have reduced side effects such as light glare, enhanced overall visual quality and enabled simultaneous astigmatism correction, resulting in high patient satisfaction. Because the optimal lens varies depending on each individual's eye condition, however, patients must undergo a thorough examination with a specialist and develop a personalized treatment plan.

Particularly careful planning is required when cataracts coexist with other eye conditions — such as glaucoma, retinal detachment or macular degeneration — that need to be treated at the same time, or when a history of refractive surgery such as LASIK or LASEK, or structural abnormalities of the eye, makes intraocular lens power calculation and the surgery itself considerably more complex. Cases also requiring heightened attention include patients with serious systemic conditions — such as severe diabetic retinopathy, cardiovascular disease or immune disorders — who need close monitoring before and after surgery, those who require general anesthesia, and those with severe traumatic eye injury.

By Kim Tae-yul, senior health and medical reporter


kty@heraldcorp.com