We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is the Ciliary Muscle?

Mary McMahon
Updated Mar 03, 2024
Our promise to you
The Health Board is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At The Health Board, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The ciliary muscle is a muscle in the ciliary body, an area of the eye which helps people focus. With the assistance of the ciliary muscle, the lens of the eye can be flattened or rounded to allow people to focus on distant and near objects. This muscle is also responsible for controlling part of the drainage system of the eye to maintain the proper fluid pressure in the eye. Damage to this muscle can lead to vision problems.

This smooth muscle is circular, surrounding the lens of the eye. It is attached to the lens with small fibers known as zonules or suspensory ligaments. When the ciliary muscle is relaxed, the ligaments are pulled taught, which flattens the lens of the eye. With a flattened lens, someone can see more distant objects. When the ciliary muscle is contracted, the ring becomes smaller, and the lens is pushed into a rounded and bulged shape which allows it to focus on near objects. The shape of the lens can be minutely adjusted for fine tuning when it comes to focus.

Incredibly rapid changes in focus are possible with the ciliary muscle. This structure in the eye also allows for very precise focusing at a wide variety of distances, which allows people to move their center of focus quickly when examining various objects in the visual field. The muscle is innervated by the third cranial nerve, also known as the oculomotor nerve, one of several nerves which plays a role in the control of eye movements.

In addition to being involved in focusing, the ciliary muscle also regulates the flow of fluid into Schlemm's canal, allowing the eye to drain aqueous humour. This fluid is constantly in production and must be drained so that the pressure in the eye remains consistent. If the eye cannot drain aqueous humour, it can build up in the eye and cause health problems. Glaucoma is an example of eye conditions characterized by elevated intraocular pressure.

This tiny muscle is best viewed under magnification so that people can see the details of the muscle structure and its point of attachment. On very high magnification, the suspensory ligaments can be seen clinging to the ciliary muscle like wisps of cotton. The apparent fragility of these structures belies the fact that they are used thousands of times a day to adjust the focus of the eye in order to meet the needs of its owner.

The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a The Health Board researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments
By Sinbad — On Jul 19, 2011

@amysamp - I am not sure about the connection either! But I think, and I could be wrong that hair cells called the cilia can't be innervated by any such cranial nerve because it is not a muscle and muscles are innervated by the cranial nerves.

Yep, I checked nerves, can be either motor or sensory. They use the term innervate to describe a motor neuron. Motor neurons have to do with muscles because they move things, hence the name motor.

So that explains that, but we still don't know why they have close to the same name!

By amysamp — On Jul 19, 2011

I was here looking for more information for the cilia in our ears, as we learn about hearing in my speech therapy courses.

Cilia are tiny cellular hairs that are a part of the hearing process, and they are what often gets injured when we listen to music too loud, but they can heal.

Anywho, when I came across this I thought it would add to that knowledge, but instead I learned some interesting information about one of our eye muscles!

Who knew that the ciliary muscle function would be to work as a contraction muscle in the eye to help us get our lens into a shape that helps us to focus on near objects, as opposed to having something to do with the cilia in the ear?

I wonder how the names are related or if it was just pure coincidence...maybe they are innervated by the same cranial nerve?

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.