Entoptic image is a visual perception that is produced by structures within the eye - in this case vitreous opacities. Patients complain of small specks or dots that can be seen against a bright background such as a diffusely illuminated wall or the blue sky. Sometimes fine dark lines in amorphous mass - like small branching twigs - are seen. These floaters move around and are also called 'muscae volitantes' because they seem to dart about like flies as the eye is moved.
Copyright Jesse Draper