How do eyes help distinguish proturans, diplurans, silverfish, and bristletails?

Eyes are a key diagnostic feature for distinguishing these groups of primitive, wingless hexapods:

• Proturans: These minute, soil-dwelling hexapods are characterized by the complete absence of eyes and antennae.12
• Diplurans: Like proturans, diplurans lack both compound eyes and ocelli (simple eyes).1
• Bristletails: Members of the order Archaeognatha possess compound eyes and three ocelli.31
• Silverfish: Classified under the order Zygentoma, silverfish show variation in their visual structures. While some families, such as Lepismatidae and Lepidotrichidae, possess eyes, others like Nicoletiidae and Protrinemuridae are eyeless.1

In summary, while bristletails consistently possess compound eyes and ocelli, proturans and diplurans are defined by their lack of eyes, and silverfish exhibit diversity in this trait depending on the specific family.1