The disks of the rod outer segment are free floating ones, but those of cone outer segment connect each other. Bothe rods and cones have connecting cilium and accessory outer segment (AOS)to connect inner and outer segment.

• 视杆外段膜盘为游离膜盘；而视锥外段膜盘相互连接；为连续的膜结构；视杆和视锥均有连接纤毛和辅助外段连接内外段；视锥的辅助外段特别明显.