Presbyopia: what it is, symptoms, treatment and when it starts

Moorfields Eye Hospital explains that the natural lens is the flexible part of the eye that enables most young people to see clearly in the distance and up close. Its flexibility diminishes with age, and by the mid-forties even people who have never needed spectacles start to need reading glasses. This age-related loss of reading vision is called presbyopia.

The NHS lists presbyopia as one of the ways in which the eyes can fail to focus properly, when the lens inside the eye becomes stiffer, usually due to ageing. That is different from long-sightedness caused by the shape of the eye or of the cornea, which can be passed on from your parents and can affect children. Presbyopia is not a disease, and it affects almost everyone as they age.

The NHS says long-sightedness can usually be treated with glasses or contact lenses, which help the eyes focus correctly so you can see nearby objects clearly. Your optician will give advice on the best options. For presbyopia this typically means reading glasses for near tasks, or bifocal or varifocal lenses that combine distance and near prescriptions, and your optometrist can talk through which suits your work and hobbies.

The NHS says contact lenses are usually only suitable for adults and may not be suitable for everyone.

Some people may be able to have laser eye surgery or lens replacement surgery. The NHS says both are carried out while you are awake, under local anaesthetic, and that laser eye surgery uses lasers to reshape the cornea while lens surgery replaces the lens inside the eye with a plastic implant. It says these treatments are not usually available on the NHS and to ask your optician whether they may be options.

The NHS lists the symptoms of long-sightedness, which include presbyopia: finding it hard to see nearby things, with words and pictures in books or on screens looking fuzzy; seeing things more clearly when you move them further away; tired eyes after tasks that involve looking at something closely, such as reading or working at a computer; and headaches.

Because the change is gradual, many people first notice holding menus or phones further away, or needing more light to read. If you already wear distance glasses you might find you need to take them off or push them up to read.

• Words and pictures in books or on screens look fuzzy up close

• Things look clearer when moved further from the eyes

• Tired eyes after reading or computer work

• Headaches

The cause is the lens inside the eye becoming stiffer with age. The NHS says long-sightedness more generally can also be caused by the shape of your eye or the shape of the front layer of your eye (the cornea), is often passed on from your parents and cannot be prevented. It can rarely be caused by other conditions such as diabetes and eye cancer.

Presbyopia is therefore not caused by reading too much, screen use or weak eye muscles, and wearing reading glasses does not make the eyes weaker.

The NHS says an optometrist will usually do an eye test, asking you to look at lights or read letters while different lenses are placed in front of your eyes, to find out how well your vision is working. They will usually shine a light into your eyes to check that the back of your eyes is healthy, and may give you eye drops to get a better look.

A sight test therefore checks eye health as well as the prescription, which is one reason it is worth having your eyes tested regularly even if you only need reading glasses.

The NHS says you are entitled to a free NHS sight test if you are under 16, 16 to 18 and in full-time education, 60 or over, registered as partially sighted or blind, diagnosed with diabetes or glaucoma, 40 or over with a close relative with glaucoma, or advised by an eye doctor that you are at risk of glaucoma. People on some benefits, including Universal Credit and Pension Credit Guarantee Credit, may also qualify.

NHS optical vouchers towards glasses or contact lenses are available to a narrower group, including children under 16 and people on certain benefits. If you do not have a voucher, you will have to pay for glasses or contact lenses yourself.

Laser and lens surgery are usually only available privately. The NHS says that you may be able to have laser surgery on the NHS if you have an eye condition that could lead to loss of vision or problems with sight that cannot be corrected by glasses or contact lenses. The NHS lists common side effects such as glare, halos and sore eyes that normally improve within a few months, and complications including a detached retina and under- or over-correction, so ask for a full consultation and explanation of the risks before choosing surgery.

Gradual blurring of near vision in your forties is expected. Sudden changes are not. The NHS says to get help from NHS 111 if floaters suddenly appear or increase in number, you get flashes of light in your vision, a dark curtain or shadow moves across your vision, or your vision gets suddenly blurred.

See an optician if you or your child have signs of long-sightedness. Children with severe long-sightedness are more likely to develop other eye problems, including lazy eye and squint, according to the NHS.