Overview
- The peer-reviewed findings, published in Scientific Reports, document telephone cord–like coils in the optic nerves of chameleons.
- Contrast-enhanced microCT scans of three distantly related species show the looping nerves are widespread in chameleons and absent in other surveyed reptiles.
- The coils yield up to roughly three times the straight brain-to-eye distance, providing mechanical slack that protects the nerves during wide eye movements.
- Embryo scans indicate optic nerves start straight and twist into coils by hatching, pointing to a programmed developmental process.
- The authors hypothesize the adaptation evolved to compensate for chameleons’ short, rigid necks that limit head rotation, with future work probing function and broader comparisons.