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 from 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 Sclera?

Niki Acker
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 sclera is the opaque part of the eye. In humans and most other mammals, it is white, and hence commonly referred to as the white of the eye. It serves to protect the inner structures of the eye and maintain the eye's spherical shape. It contains collagen and elastic fiber. The muscles responsible for eye movement are also attached to the sclera.

The whites of the eyes are provided with many blood vessels, mostly on the surface. The eye is also covered with the conjunctiva, a clear mucous mebrane that also lines the inner eyelids. When the eyes are inflamed, the blood vessels of the sclera and the conjunctiva make them appear red.

While the mammalian sclera consists of connective tissue only, in some animals, it is strengthened by a structure called the scleral ring. Birds, some reptiles, and some fish have a scleral ring. It is made up of plates of bone or cartilage.

Some animals, including horses and some lizards, have a black sclera. In children, the whites of the eyes are less opaque and can appear somewhat blue, while in the elderly, fat deposits can make the whites of the eyes appear yellowish. Scleral melanocytosis is a harmless condition in which small blue-grey spots appear on the white of the eye.

The sclera has four layers, all made of connective tissue. The outermost layer is the episclera, which covers a layer of stroma. Underneath the stroma is the lamina fusca, and the innermost layer is the corneal endothelium. The corneal endothelium, as you may have guessed by its name, is shared by the sclera and the cornea, the transparent front part of the eye where the iris and pupil are located.

In addition to being continuous with the cornea, the sclera is also continuous with the dura mater, the outermost of the three meninges, membranes covering the brain. The white of the eye connects with the dura mater at the optic disc, located at the back of the eye. The optic disc is the location where the optic nerve exits the eye to carry visual information to the brain.

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.
Niki Acker
By Niki Acker , Writer
"In addition to her role as a The Health Board editor, Niki Foster is passionate about educating herself on a wide range of interesting and unusual topics to gather ideas for her own articles. A graduate of UCLA with a double major in Linguistics and Anthropology, Niki's diverse academic background and curiosity make her well-suited to create engaging content for WiseGeekreaders. "

Discussion Comments

Niki Acker

Niki Acker


"In addition to her role as a The Health Board editor, Niki Foster is passionate about educating herself on a wide range...
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.