how is it related to the guillain disease?
They are not affected by it.
Optic nerve
Peripheral neuropathies like Guillain–Barré syndrome do not affect the optic nerve. 
where do the cranial nerves branch off the brain The terminal nerves; olfactory nerves and optic nerves emerge from the cerebrum, and the remaining ten pairs arise from the brainstem, which is the lower part of the brain. what do they do? They relay information between the brain and parts of the body. do they have a nucleus? All cranial nerves have a nucleus. With the exception of the olfactory nerve and optic nerve, all the nuclei are present in the brainstem. what is this first type of nerve? It is typically considered the first cranial nerve, or simply CN I, that contains sensory nerve fibers relating to the sense of smell. and what about the second type? It is known as cranial nerve II, or simply as CN II, a paired cranial nerve that transmits visual information from the retina to the brain. what ailments can cn ii suffer from? Damage to the optic nerve typically causes permanent and potentially severe loss of vision, as well as an abnormal pupillary reflex. what is its form or shape like? It is derived from an out-pouching of the diencephalon (optic stalks), the fibers of the optic nerve are covered with myelin.
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Optic nerve [SEP] Structure
The optic nerve has been classified as the second of twelve paired cranial nerves but it is technically part of the central nervous system, rather than the peripheral nervous system because it is derived from an out-pouching of the diencephalon (optic stalks) during embryonic development. As a consequence, the fibers of the optic nerve are covered with myelin produced by oligodendrocytes, rather than Schwann cells of the peripheral nervous system, and are encased within the meninges. Peripheral neuropathies like Guillain–Barré syndrome do not affect the optic nerve. However, most typically the optic nerve is grouped with the other eleven cranial nerves and is considered to be part of the peripheral nervous system.