What is the optic nerve disc?

What is the optic nerve disc?

The optic disc is the round spot on the retina formed by the passage of the axons of the retinal ganglion cells, which transfer signals from the photoreceptors of the eye to the optic nerve, allowing us to see.

What is the optic disc called?

optic nerve head
The optic disc (optic nerve head) is the location where ganglion cell axons exit the eye to form the optic nerve. There are no light sensitive rods or cones to respond to a light stimulus at this point. This causes a break in the visual field called “the blind spot” or the “physiological blind spot”.

What is the normal optic disc?

The average human optic disc dimensions are 1.88mm vertically by 1.77mm horizontally, and can be grouped by vertical diameter into small (1.2-1.7mm), average (1.87-1.96mm), and large (2.03-2.27mm) disc sizes [1].

What are symptoms of optic nerve damage?

Eye and vision symptoms of optic nerve damage

• Abnormal pupil size and nonreactivity to light.
• Bulging of the eyes.
• Complete or partial loss of vision.
• Diminished ability to see fine details.
• Diminished color vision or colors seem faded.
• Dimming or blurring of vision.
• Double vision.
• Eye redness.

What causes optic nerve damage?

What Causes Optic Nerve Damage? Optic nerve damage case be caused by eye diseases like glaucoma, poor blood flow (ischemic optic neuropathy), shock or trauma, toxins such as lead or carbon monoxide, radiation, or diseases of the central nervous system.

Is optic nerve nasal or temporal?

Because the crossing optic nerve fibers come from the nasal retina, the lateral (temporal) visual field is affected.

What is the function of the optic nerve?

The optic nerve is a bundle of more than 1 million nerve fibers. Also known as the second cranial nerve or cranial nerve II (CNII), it is the second of several pairs of cranial nerves. It transmits sensory information for vision in the form of electrical impulses from the eye to the brain.

Is optic nerve a true nerve?

The myelinated orbital portion of the optic nerve can be considered more a tract of the brain than a true cranial nerve. The optic nerve is continuous at one end with the retina and at the other end with the brain, making it vulnerable to a variety of both ocular and central nervous system (CNS) diseases.

What is disc eye?

Optic disc: The circular area in the back of the inside of the eye where the optic nerve connects to the retina. Also called the optic nerve head.

How big is the optic nerve?

The optic nerve component lengths are 1 mm in the globe, 24 mm in the orbit, 9 mm in the optic canal, and 16 mm in the cranial space before joining the optic chiasm. There, partial decussation occurs and about 53% of the fibers cross to form the optic tracts.

Can the optic nerve be repaired?

In the case of the optic nerve, it is a person’s vision that is lost or impaired. The optic nerve is part of the central nervous system and cannot regenerate or repair itself because of natural inhibitors in the body that block its re-growth.