What Is Presbyopia?

Presbyopia is a vision condition that develops as a result of the lens in the eye becoming rigid over time as an outcome of ageing.

This can easily be treated with prescription glasses and is easily managed regularly with the option of support from public health services.

Keep reading to find out more about the signs to look out for with presbyopia, what it is caused by, and how it is diagnosed.

Overview

For objects to appear clear and in focus, the lens in the eye has to change shape to allow light to be refracted (bent) precisely and focussed onto the retina (found at the back of your eye).¹

This process is called accommodation because the lens must accommodate changes in shape when looking at objects at different depths of field, i.e. at different distances from your eyes. To focus on a near object – the lens becomes thicker, which allows the light rays to refract (bend) more strongly. In other words, looking at an object closer to you compared to an object further away would cause the shape of your lens to thicken.

Many people require glasses early in their lives for either myopia (difficulty seeing objects far away) or hyperopia (struggling to see objects close up). This is usually due to the shape of the eye, caused by genetics or other conditions. 

However, presbyopia is a natural part of ageing. It happens because the lens becomes less flexible and therefore, stops being able to change shape as well as it could previously and, therefore, cannot refract (bend) light over the necessary range to allow objects that are close to being fully focussed on the retina. Therefore, objects up close to the face are no longer perceived clearly (in sharp focus) but are in fact, blurry.²

Causes of presbyopia

Presbyopia is a natural result of the process of ageing. As a person gets older, so do the lenses in the eye, meaning they begin to stiffen up. With less capacity for accommodation, the lenses can no longer focus the light entering your eye correctly, making things seem much blurrier. This loss of lens function generally begins around the age of 40, and can gradually worsen until around 65 years of age.³ 

In addition, having certain diseases, such as diabetes, multiple sclerosis or cardiovascular disease, can increase your risk of premature presbyopia i.e. presbyopia before the age of 40.

Signs and symptoms of presbyopia

Presbyopia can primarily present as difficulty reading. Other signs of presbyopia may also be present, such as: 

• Difficulty focusing on objects or text at close distances
• To view close objects clearly, an increased distance is required between them and the eyes to see them clearly
• Eye fatigue, discomfort or soreness
• Headaches, often experienced after prolonged periods of close-up work or reading
• Blurred vision when attempting to view nearby objects
• Eye discomfort or strain when engaged in activities that require near vision, such as reading, writing, or using electronic devices
• Squinting or straining the eyes in order to see things up close clearly.⁴

Management and treatment for presbyopia

The majority of people with presbyopia will generally be treated with corrective glasses or contact lenses. This works by correcting the refractive errors in the eye by altering the angle of the light entering the eye so that light can correctly be focused on the retina. Different degrees of presbyopia will require different thicknesses of glass lenses, which will be decided through an eye test, and the resulting lens prescription will be given by an optician or eye doctor.⁵

Corrective glasses

People who already have glasses for myopia (difficulty seeing distant objects clearly) may decide to get bifocal or multifocal glasses, which contain both lens prescriptions for seeing near and far so that they don’t need a separate pair of glasses for each range of distance. Bifocal glasses have a distinct line in the centre of the spectacle lens, dividing the point where the long-distance corrective lens finishes and the short-distance corrective lens begins. On the other hand, multifocal spectacles lenses have the same appearance as a single vision lens, but the lens actually gradually changes in prescription in a graduated manner down the lens, meaning there is accommodation for all distances.⁵ An optician or eye doctor can help you make the best decision regarding the most appropriate type of lenses for you.

Contact lenses

Contact lenses are also a great option for correct vision and work in the same way as corrective glasses. Many people prefer contact lenses due to their apparent weightlessness and invisibility, especially if they haven’t worn glasses previously. 

Again, an optometrist can advise you on whether they are a good solution for you. In helping you decide, they may discuss and take into consideration your lifestyle, such as whether you play any sports or have requirements arising from other hobbies, as well as the kind of work you do from day to day.

Sometimes, a combination of contact lenses and corrective glasses may be found to be the optimum treatment for both near and far vision.⁵

Laser surgery

Laser surgery cannot provide a cure for presbyopia, as it is a condition in which the vision deteriorates over time and won’t usually stop progressing until the age of 65. LASIK (short for laser in situ keratomileusis) involves removing corneal tissue to reshape the cornea, which helps with vision correction.⁶ However, there is no guarantee that it will mean you won’t have to wear glasses or use another corrective measure.

Lens implant surgery

Bifocal or multifocal lens implant surgery is a relatively new procedure used to address long-sightedness. It involves the insertion of an artificial lens into the eye through a small incision in the cornea.⁵ These specialised lenses are designed to enhance the focus of light onto the retina and thus improve clarity of vision.

For individuals who already use reading glasses, the primary option is natural lens replacement with an artificial one. This involves the removal of the natural lens and its replacement with an artificial lens, in a similar way to cataract surgery. 

The lens removal and implantation are typically performed under local anaesthesia, and you can usually return home on the same day. Each eye is usually treated separately on different occasions. 

While current artificial lens technology aims to reduce the need for glasses post-surgery, it cannot guarantee complete freedom from glasses.⁵ As with any medical procedure, there are risks associated with the surgery to implant artificial lenses in the eyes. 

It is crucial to discuss each procedure thoroughly with your doctor or surgeon to fully understand the associated risks. These procedures can also be very expensive and are generally only available through private healthcare providers.

Diagnosis of presbyopia

A local optometrist or optician can diagnose presbyopia through a routine sight test or eye examination.⁴ This can include a discussion with the eye doctor about any concerns you have about your vision or eye problems, as well as a more general inquiry about your lifestyle, occupation, family history and current medication.

Some tests are also usually carried out and include:

• Photographing the retina or back of the eye  
• Assessing your peripheral vision using a visual field test
• Trying a range of different lenses in front of your eyes to establish if they improve or decrease your ability to see clearly
• Use screens or text to see if you can read at standard distances⁴

These checks are used to rule out any other conditions that could be causing vision problems, as well as help to determine the lens prescription required if you need glasses or contacts.

Risk factors for presbyopia

Age is the biggest risk factor for presbyopia because the lenses in your eyes begin to degenerate gradually after the age of 40. However, diseases such as diabetes, multiple sclerosis or cardiovascular disease can increase your risk of having presbyopia earlier than age 40. 

UV light exposure has also been hypothesised to affect the degradation of the lens, leading to the premature onset of presbyopia. This means in countries closer to the equator, the risk of presbyopia may be higher, or symptoms may start at an earlier age.⁵ Wearing sunglasses and protecting the eyes from UV light can slow its impact.

Presbyopia is more common in women aged 40 and above in comparison to men in the same age bracket.⁵ This greater need for correction of presbyopia correction among women than among men is believed to stem from differences in the tasks performed and the viewing distances they require rather than physiological differences in accommodation mechanisms arising from gender.⁷

FAQs

How can I prevent presbyopia?

Currently, there is no known method of preventing presbyopia. However, it can be managed or treated. Corrective measures such as prescription glasses or contact lenses are readily available. An optician can also advise on surgical procedures such as laser surgery or lens transplant.

How common is presbyopia?

Presbyopia is extremely common, with approximately 85% of people over 40 developing the eye condition.⁵

When should I see a doctor?

If your near vision becomes blurry or unfocussed, or if you start to struggle reading text up close, such as small print in books and newspapers, food labels, or instructions, an optician can help correct your vision to make it clearer.

Summary

Presbyopia is an age-related condition where the lens in the eye loses flexibility, causing difficulty in focusing on nearby objects. Symptoms include blurry vision, the need for increased reading distance, eye fatigue, headaches, and reduced ability to see fine details. Diagnosis involves a comprehensive eye examination. Age is the main risk factor, while UV exposure and gender differences may also contribute. Presbyopia can be managed with prescription glasses, contact lenses, or surgical procedures like laser surgery or lens implant surgery. However, the latter procedures do not guarantee freedom from glasses and carry potential risks. Opticians can provide suitable treatment options based on individual needs.