Skip to main navigation Skip to main content Skip to footer For Medicare For Providers For Brokers For Employers Español For Individuals & Families: For Individuals & Families
Shop for Plans

Shop for Plans
Shop for your own coverage
Medical Dental Other Supplemental
Plans through your employer

Learn about the medical, dental, pharmacy, behavioral, and voluntary benefits your employer may offer.

Explore coverage through work
Learn
How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics
Looking for Medicare coverage?
Shop for Medicare plans
Member Guide
Find a Doctor
Medical Dental Other Supplemental Explore coverage through work How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics Shop for Medicare plans Member Guide Find a Doctor Log in to myCigna
Home Knowledge Center Wellness Library Eye Structures (Front and Side Views)

Eye Structures (Front and Side Views)
Parts of the eye (outer view)
Parts of the eye (cross section)

The conjunctiva is the mucous membrane that lines the eyelid and eye surface. In a healthy eye, the conjunctiva is clear and colorless.

The sclera is the tough outer layer of the eyeball (the white of the eye). The slight bulge in the sclera at the front of the eye is a clear, thin, dome-shaped tissue called the cornea. The cornea directs light rays into the eye and helps focus them on the retina.

The pupil is the opening in the colored part of the eye (iris). It allows light to pass to the lens. The iris controls the size of the pupil in response to light outside the eye so that the proper amount of light is let into the eye.

The lens is normally clear and is located behind the iris. Small muscles attached to the lens can change its shape. This allows the eye to focus on near or far objects.

Vitreous gel (also called vitreous humor) is a thick liquid that fills the eye. It helps the eyeball keep its shape.

The retina is a thin nerve tissue that lines the back of the eye. It detects light entering the eye and converts it into electrical impulses. The optic nerve carries the impulses to the brain. The brain interprets the impulses as the things that you see.

The macula is part of the retina. The macula provides the sharp, detailed, central vision that allows you to focus on what is directly in the line of sight. The rest of the retina provides side (peripheral) vision, which allows you to see shapes but not fine details.

Current as of: September 27, 2023

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

To learn more about Ignite Healthwise, LLC, visit webmdignite.com.

© 2024 Ignite Healthwise, LLC. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Ignite Healthwise, LLC.

<cipublic-spinner variant="large"><span>Loading…</span></cipublic-spinner>

Page Footer

I want to...

Get an ID card File a claim View my claims and EOBs Check coverage under my plan See prescription drug list Find an in-network doctor, dentist, or facility Find a form Find 1095-B tax form information View the Cigna Glossary Contact Cigna

Audiences

Individuals and Families Medicare Employers Brokers Providers

Secure Member Sites

myCigna member portal Health Care Provider portal Cigna for Employers Client Resource Portal Cigna for Brokers

The Cigna Group Information

About Cigna Healthcare Company Profile Careers Newsroom Investors Suppliers The Cigna Group Third Party Administrators International Evernorth

 Cigna. All rights reserved.

Privacy Legal Product Disclosures Cigna Company Names Customer Rights Accessibility Non-Discrimination Notice Language Assistance [PDF] Report Fraud Sitemap Cookie Settings

Disclaimer

Individual and family medical and dental insurance plans are insured by Cigna Health and Life Insurance Company (CHLIC), Cigna HealthCare of Arizona, Inc., Cigna HealthCare of Illinois, Inc., Cigna HealthCare of Georgia, Inc., Cigna HealthCare of North Carolina, Inc., Cigna HealthCare of South Carolina, Inc., and Cigna HealthCare of Texas, Inc. Group health insurance and health benefit plans are insured or administered by CHLIC, Connecticut General Life Insurance Company (CGLIC), or their affiliates (see a listing of the legal entities that insure or administer group HMO, dental HMO, and other products or services in your state). Accidental Injury, Critical Illness, and Hospital Care plans or insurance policies are distributed exclusively by or through operating subsidiaries of Cigna Corporation, are administered by Cigna Health and Life Insurance Company, and are insured by either (i) Cigna Health and Life Insurance Company (Bloomfield, CT); (ii) Life Insurance Company of North America (“LINA”) (Philadelphia, PA); or (iii) New York Life Group Insurance Company of NY (“NYLGICNY”) (New York, NY), formerly known as Cigna Life Insurance Company of New York. The Cigna name, logo, and other Cigna marks are owned by Cigna Intellectual Property, Inc. LINA and NYLGICNY are not affiliates of Cigna.

All insurance policies and group benefit plans contain exclusions and limitations. For availability, costs and complete details of coverage, contact a licensed agent or Cigna sales representative. This website is not intended for residents of New Mexico.

Selecting these links will take you away from Cigna.com to another website, which may be a non-Cigna website. Cigna may not control the content or links of non-Cigna websites. Details