Barrier is a synonym of Fence. Fence is related to Field. Field is a synonym of Sphere. Sphere is a synonym of Sector. 
Camera is related to Eye. Eye is related to One. 
Barrier <--Synonym--> Fence <--RelatedTo--> Field <--Synonym--> Sphere <--Synonym--> Sector 
Camera <--RelatedTo--> Eye <--RelatedTo--> One 