Prions have an affinity to these areas except:

Prions are misfolded proteins that are associated with a group of neurodegenerative diseases. They primarily target the nervous system and have a strong affinity for brain tissue and spinal cord tissue, which are rich in neuronal cells where prion diseases manifest, leading to conditions such as Creutzfeldt-Jakob disease and bovine spongiform encephalopathy.

The eye is not typically associated with prion accumulation or pathology. While the eye can be affected indirectly in systemic prion diseases, it does not have the same direct affinity that the brain and spinal cord do. Therefore, the correct understanding is that prions specifically tend to target the central nervous system structures—primarily the brain and spinal cord—but not the eye, making the eye the exception in this context.

When considering the response "None of the above," it indicates that all mentioned areas were considered in terms of prion affinity, but the eye is indeed the area that does not share the same level of affinity as the others listed. Thus, the correct answer reflects the specificity of prion disease manifestation and their primary sites of influence within the central nervous system.