What is an Intraocular Lens?

The intraocular lens is a tiny piece of plastic that's so important to our work that we use it in our logo. Fred Hollows once called them "the most expensive pieces of plastic in the world". Today, these tiny lenses help restore sight to millions of people through cataract surgery.

How intraocular lenses restore vision

An intraocular lens (IOL) is an artificial lens implanted inside the eye during cataract surgery to replace the eye's natural lens after it has become cloudy. It restores clear vision by focusing light onto the retina, just as the natural lens does.

During cataract surgery, the cloudy natural lens is removed and replaced with a clear synthetic lens. This tiny, precisely designed implant makes sight-restoring cataract surgery possible for millions of people around the world.

Since Fred Hollows was alive, the cost of intraocular lenses has fallen dramatically, making cataract surgery more affordable in many parts of the world.

Cataracts commonly occur as part of ageing. However, when very young children develop cataracts, surgery may sometimes be performed without immediately implanting an IOL because their eyes are still developing. Glasses are used until an ophthalmologist determines the right time to implant the lens.

The story of a little piece of plastic making a huge difference

Professor Fred Hollows revolutionised cataract surgery in the developing world with the Intraocular Lens, an $8 lens that has restored sight to millions around the world. This is how it's made.

How does the IOL work?

The natural lens of the eye focuses light onto the retina so we can see clearly. When a cataract develops, the lens becomes cloudy and vision becomes blurred. During cataract surgery, the cloudy lens is removed and replaced with an intraocular lens (IOL), restoring clear vision.

Light travels through the natural lens and is brought to focus on the retina at the back of the eye. The retina transforms the light stimuli into electrical impulses that are carried by the optic nerve to the brain. We perceive the light reflected off surfaces as an image.

The IOL works in the same way as the natural lens, except that it’s made of materials such as a plastic commonly called Perspex.

The IOL’s shape and size are designed to fit perfectly inside the lens capsule. A stable and centered IOL provides the best chance of correct focus and clear vision.

How were low-cost IOLs produced?

Cataract is the leading cause of blindness globally - and IOLs are an integral part of restoring sight to someone with cataract.

When Fred was alive, IOLs were expensive – which meant that low-cost cataract surgery was considered an impossibility. However, Fred put the pieces in place to create state-of-the-art intraocular lens factories in Nepal and Eritrea.

The aim was to produce high-quality, low-cost intraocular lenses and meet the needs of the cataract blind in developing nations.

Learn more about how Fred Hollows made cataract surgery affordable for millions through low-cost intraocular lenses.

IOL factories

Both laboratories in Eritrea and Nepal opened in 1994 and are now locally managed and independent. They produce around 250,000 lenses every year, which are distributed to more than 50 countries. The creation of these factories meant that one of the biggest costs in cataract surgery was reduced – and by doing this, the ability to perform low-cost surgeries in developing countries has become a reality.

The factories have produced almost eight million lenses since they opened.

Producing low-cost IOLs and finding other ways to minimise the cost of consumables and surgical equipment, means The Foundation has helped make cataract surgery affordable in many disadvantaged communities.

What’s more, the IOL factories provide a world-class, high-technology manufacturing base, generating new export markets for Eritrea and Nepal.

These amazing pieces of plastic are the reason The Foundation can perform a cataract operation for as little as $25.

Frequently asked questions about IOLs

Is an IOL permanent?

Yes. In most cases, an intraocular lens is designed to last for the rest of a person's life and does not need to be replaced.

Can you feel an IOL in your eye?

No. Once implanted, people generally cannot feel an intraocular lens because it sits inside the eye where the natural lens used to be.

Are IOLs safe?

Modern intraocular lenses are widely used around the world, and cataract surgery is one of the most commonly performed operations. An ophthalmologist can explain the benefits and risks based on your individual circumstances.

How long does an IOL last?

Most intraocular lenses are designed to last a lifetime.

What is an IOL made from?

Modern IOLs are made from medical-grade materials such as acrylic or silicone. Earlier lenses, including those championed by Fred Hollows, were commonly made from PMMA (Perspex).

Does cataract surgery always include an IOL?

For adults, an IOL is implanted in almost every cataract operation. In some babies and young children with cataracts, doctors may delay implantation until the eye has developed further.

What types of intraocular lenses are available?

There are several types of IOLs used in cataract surgery, including:

Monofocal IOLs, which provide clear vision at one distance.
Multifocal IOLs, which can help people see at multiple distances.
Toric IOLs, which are designed to correct astigmatism.

The most suitable IOL depends on a person's eye health, vision needs and lifestyle. An ophthalmologist can recommend the best option.

How much does an IOL cost?

The cost of an intraocular lens varies depending on the country, healthcare system and type of lens used. When Professor Fred Hollows began his work, IOLs were one of the biggest costs associated with cataract surgery. By helping establish low-cost manufacturing, he played a key role in making cataract surgery more affordable in many parts of the world.