The present invention provides methods of screening an agent for an activity in an isolated organ, e.g., eye, from a teleost, e.g., zebrafish. Methods of isolating eyes from zebrafish are provided. Methods of screening an agent for an ocular activity in the isolated eye are provided. Methods of screening an agent for an ocular activity in a model of ocular disease or disorder are provided. Methods of screening an agent for an ocular activity in the isolated eye and for screening the agent for cell death and/or toxic activity in the eye or other organ or tissue are provided. The invention further provides high throughput methods of screening agents for an activity in isolated eyes of zebrafish in multi-well plates.