Human T-lymphotropic virus type 1 (HTLV-I) has an etiologic role in adult T-cell leukemia (ATL) and HTLV-I associated myelopathy (HAM). This paper reviews the ophthalmic literature relevant to the retrovirus. Patients with ATL may have intraocular invasion of proliferated T lymphocytes, lymphomatous lesion in the ocular adnexa, or cytomegalovirus retinitis due to immunocompromisation. Patients with the chronic neurological disease HAM may present with retinal vasculitis, isolated cotton-wool spots, probably immune-mediated uveitis, and/or retinochoroidal degenerative change. Similar retinal vascular or uveal inflammatory disease is occasionally seen in otherwise healthy HTLV-I carriers. Clinical and epidemiologic data suggest the existence of HTLV-I associated uveitis (HAU) that is assumed to be associated with the retrovirus. Further ophthalmic research is encouraged to elucidate the clinical significance of the worldwide HTLV-I infection.