Hint: The supporting wall of the human eye is known as sclera. It is an opaque, fibrous, and protective outer layer of the human eye. The sclera maintains the shape of the eye balls.
Complete answer: The human eye is an important sense organ which is associated with vision. It converts the visual signals to electrochemical signals of the neurons. The eye is a complex structure which is made up of lens, cornea, iris, pupil, lens, nerves, blood vessels etc.
Let us discuss the sclera. The white portion of the eye is known as sclera. It is also known as tunica albuginea oculi. It is an opaque, protective, fibrous, outer layer of the human eye which consists of several collagen and elastic fibres. It is white and fibrous and is present in the contrasting colours than that of iris. The sclera is thinner in case of children whereas in elderly it appears as yellowish due to the deposition of fat.
The sclera is continuous with the dura mater and cornea. It has many perforated nerves and blood vessels that pass through the posterior scleral foramen which is formed by the optic nerve. The blood vessels are present on the surface of the sclera.
Function of sclera: 1)It maintains the shape of the eye by balancing the internal and external resistive forces. 2)It provides attachment for the extraocular muscles. 3)It serves as an important tool in non-verbal communication.
Note: The bony socket around the eye protects the sclera. The injury from the sharp object can result in complete vision loss. It is resistant to the exposure of toxic chemicals. The yellow sclera is a significant symptom of jaundice. In certain kidney and liver failure, it turns black.