Presbyopia: why near vision fades with age and what helps

Sooner or later it happens to almost everyone: the menu goes blurry, your phone drifts further and further from your face, and your arms suddenly seem too short for reading. This is not a disease but presbyopia – a term derived from the Greek for ‘old eye’.

What happens in the lens

To switch between distance and near, your eye adjusts its focusing power – a process called accommodation. The lens is suspended by fine fibres called zonules. The surprising part: to focus up close, the ring-shaped ciliary muscle contracts. This slackens the fibres, allowing the elastic lens to become rounder – and its focusing power increases.

It is precisely this flexibility that is lost over the years; according to the American Academy of Ophthalmology (AAO), the lens becomes noticeably more rigid after about 40. Just how much was shown by a 2004 Australian laboratory study of 18 donor lenses from people aged 14 to 76: across this span, the stiffness of the lens nucleus rose on average by a factor of 450, and that of the outer cortex by a factor of about 20. The water content of the nucleus, by contrast, stayed practically unchanged – so the lens does not simply ‘dry out’. Contributing factors include lens proteins that become glycated and cross-linked over time and the thickening of the lens.

You can measure the effect at the near point – the shortest distance at which you can still focus sharply. According to the medical reference StatPearls, it lies at about 10 centimetres at age 20 and at roughly 50 centimetres at age 50 – beyond the usual reading distance.

When it starts and who is affected

Most people notice the first signs shortly after their 40th birthday. Typical signs include:

• You hold books, labels or your phone further away to see them clearly.
• Close-up vision is harder in dim light or after reading for a while.
• Your eyes tire more quickly, and some people get headaches.

By around age 60, presbyopia is almost universal, according to StatPearls. Estimates put the number of people affected worldwide at around 1.8 billion, and the figure is expected to exceed 2.1 billion by 2030. It progresses gradually: at first, a reading addition of +0.75 to +1.25 dioptres is often enough, while after the age of 55 people frequently need +2.50 dioptres or more. According to the AAO, the ageing of the lens cannot be stopped; StatPearls notes, however, that good lighting and larger text on screens make close work easier.

Incidentally, presbyopia is not the same as long-sightedness (hyperopia), even though it is sometimes loosely described as age-related long-sightedness. Long-sighted people do, however, often notice presbyopia earlier.

Why short-sighted people experience it differently

In short-sighted people, the uncorrected eye is already set up for short distances. Many therefore simply take off their glasses to read or look over the top of their frames – and so notice presbyopia later or less clearly.

That does not make them immune: their lens ages just the same, and when they wear glasses or contact lenses for distance, they face the same problem up close as everyone else.

Your options at a glance

The AAO lists these options; which one suits you depends on your eyes, your daily life and your expectations:

Reading glasses: Ready-made reading glasses are easy to buy, but the AAO recommends having the right strength determined during an eye examination. Stronger is not better: a slightly conservative correction leaves room for your remaining accommodation and increases depth of focus.

Monovision: Usually the dominant eye takes care of distance. According to the AAO, your brain first has to get used to seeing this way, and StatPearls notes that depth perception and contrast sensitivity can decrease. The AAO therefore mentions the option of trying monovision with contact lenses before deciding on laser surgery such as LASIK.

Lens exchange: In refractive lens exchange, multifocal artificial lenses aim to provide clear vision at several distances. A 2016 Cochrane review analysed 20 randomised trials with 2,061 participants – although in cataract surgery, where the lens is also replaced. People with a multifocal artificial lens were less likely to need additional glasses and tended to see better up close, with distance vision similar to that of a single-focus lens. However, they reported haloes (rings around lights) roughly three and a half times as often, and glare more frequently. According to the Cochrane authors, whether the benefit outweighs these drawbacks probably depends on how much it matters to you to depend less on glasses. StatPearls adds that multifocal artificial lenses can also reduce contrast sensitivity, especially in low light.

There is another point to consider: lens exchange is surgery inside the eye in which a lens that is still clear is removed. A 2025 review of 40 studies concluded that retinal detachment may occur roughly twice as often after refractive lens exchange as after cataract surgery (with at least two years of follow-up). According to a correction the authors published later, this affects around 1 in 50 eyes after lens exchange and slightly fewer than 1 in 100 after cataract surgery. The evidence is limited, however, and the figures may be overestimated because short-sighted eyes were probably over-represented. A thorough pre-assessment and counselling are therefore part of the process.

Eye drops: what they can and cannot do

In October 2021, the US Food and Drug Administration (FDA) approved eye drops specifically for presbyopia: pilocarpine 1.25%, originally marketed as Vuity; according to the AAO, drops containing the active ingredient aceclidine are now also available in the US. The drops make the pupil smaller, which helps the eye focus on near objects. According to the AAO, the effect lasts for up to about six hours, and the drops need to be used every day.

According to the FDA prescribing information, in two approval studies with 750 participants aged 40 to 55, after 30 days – each time three hours after the drop – 31 and 26 per cent respectively gained at least three lines on a near-vision chart in dim light, compared with 8 and 11 per cent with drops containing no active ingredient. The effect peaked after around an hour; after six hours, only 18 and 16 per cent achieved this improvement. So some people benefited clearly, but the majority did not.

The prescribing information also notes:

• Common side effects include headache and red eyes.
• Vision may temporarily appear dimmer – take care when driving at night and in poor light.
• Rare cases of retinal tears and retinal detachment have been reported; an examination of the retina is recommended before starting treatment.

The drops do not change the underlying cause. The approvals mentioned relate to the US; whether such drops are an option for you is a question for your ophthalmologist.

When to seek medical advice

An examination is worthwhile if close-up vision is becoming increasingly difficult – not least because not every near-vision problem is presbyopia: specialists rule out, for example, undetected long-sightedness or dry eyes. Also have it checked promptly if your near vision deteriorates suddenly or well before 40, or if you see double – that does not fit the typical, gradual pattern. Take note if, later in life, your near vision gradually improves again even though you previously needed reading glasses. This can be a sign of an early cataract: the hardening core of the lens can shift the eye towards short-sightedness. According to StatPearls, this ‘second sight’ is only temporary.

See an ophthalmologist or go to an emergency department immediately if you notice these warning signs, which according to the US National Eye Institute can indicate a retinal detachment:

• many new dark spots or threads floating in your vision
• flashes of light in one or both eyes
• a dark shadow or ‘curtain’ at the side or in the middle of your field of vision

Sudden loss of vision is also an emergency. You can read more in our guide to flashes and floaters.

At My Laser Vision in Wallisellen, measuring visual acuity and dioptres is part of the basic examinations in ophthalmology; if you are considering lens exchange, you can first book a free pre-assessment lasting around 30 minutes.