Oestrus ovis or 'sheep botfly' causes common ophthalmomyiasis in warm climates. It is a self-limited infestation with symptoms such as foreign body sensation and/or tearing. The larvae can be observed in the conjunctiva and should be extracted with forceps. The development of larvae beyond the first stage does not occur in healthy humans, although they may penetrate the ocular globe, causing so-called internal myiasis. External ophthalmomyiasis is typical of rural areas, but it may be observed occasionally in urban environments.