SIGNIFICANCE:Lyme disease can have widespread and long-lasting systemic implications, and ocular manifestations of Lyme disease may be the only presenting symptoms of infection. As such, eye care providers can play a critical role in facilitating the diagnosis and treatment of this disease. PURPOSE: This case report describes an isolated sixth nerve palsy secondary to Lyme disease, which is a rare neuro-ophthalmic presentation. This report emphasizes the importance of considering Lyme disease in the setting of atypical nerve palsies to allow for appropriate treatment and prevent long-term complications of untreated disease.CASE REPORT: A 63-year-old man presented with new-onset, painful diplopia for 1 day and was diagnosed with a right sixth nerve palsy. His medical history was significant for relapsing polychondritis with associated ocular complications, so his nerve palsy was presumed secondary to a flare of his systemic disease. However, secondary to complaints of new night sweats, infectious etiologies were also considered. The patient was initially treated with oral steroids with no improvement in his diplopia after being admitted to the hospital for further workup. Approximately 1 week after presentation, Lyme titers returned positive, and the diagnosis was revised to abducens palsy secondary to Lyme disease. The patient's nerve palsy rapidly resolved after oral therapy with doxycycline.CONCLUSIONS: Lyme disease is a systemic illness that can have widely varying manifestations, including ocular findings. Eye involvement may be the only presenting symptom, allowing eye care providers to serve an important role in disease recognition and management.