Our eyes, one of the most crucial parts of our body, are made up of several complex structures, including the sclera and conjunctiva. The sclera, also known as the white of the eye, is a thick protective layer. On the other hand, the conjunctiva is a thin, clear layer that covers the sclera, excluding the cornea.
Here, we delve deeper into the characteristics of the sclera and conjunctiva.
The sclera, or the white of the eye, is a dense, fibrous layer that provides the eye's outer protection. It's also known as tunica albuginea oculi in scientific terms and is composed of collagen and elastic fibers.
The sclera's noticeable layer helps others determine where someone is looking. It also aids in maintaining the eye's round shape and serves as an attachment point for eye muscles.
The sclera's color in humans contrasts with that of the iris, while in other vertebrates, the sclera's color matches the iris. If the sclera's color changes to yellow or pale, it could be a sign of jaundice.
The conjunctiva, a clear membrane, covers the sclera except for the cornea. It is composed of non-keratinized, stratified columnar epithelium, stratified squamous epithelium with goblet cells, and stratified cuboidal epithelium. This structure is highly vascularized, filled with many microvessels.
The conjunctiva secretes tears and mucus, which lubricates the eyes. It also acts as a barrier to microbes entering the eyes.
Inflammation of the conjunctiva leads to a common eye disease known as conjunctivitis.
Sclera |
Conjunctiva |
|---|---|
Description |
|
The sclera is a dense connective tissue forming the white of the eye. |
The conjunctiva is a clear membrane covering the sclera and lining the eyelids. |
Vascularisation |
|
Less vascularised. |
Highly vascularised. |
Thickness |
|
0.5mm |
0.013mm |
Function |
|
|
|
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Also Read:
Is the cornea part of the conjunctiva?
No, the cornea is not a part of the conjunctiva.
What are retinas?
The retina is a layer of tissue that contains millions of light-sensitive cells that is responsible for sensing visual information.
What is the difference between conjunctiva and cornea?
Conjunctiva is a thin layer that covers the sclera of the eye, whereas the cornea is the transparent part that covers the front portion and pupil of the eye.