In the last decade, lipid based emulsions (LEs) have emerged as a novel tool in ophthalmic drug delivery from the aspect of improved bioavailability (BA). Recent research is focuses on two main approaches for BA improvement i.e., by enhancing the corneal permeability and increasing the retention time of drug on the ocular surface. The LEs have great potential to delivery hydrophobic drug because drug molecules get dissolve in oil globule and main advantage associated are reduced toxic effect and improved self-life of drug molecule. Ophthalmic drug delivery is always an interesting and challenging task for the pharmacologists and formulation scientists due to the unique structure of eye. Development of drug delivery system and its delivery to target receptor of the eye is very difficult for scientists due to the strong defense mechanism of eye. In this review, the focus is to explore key concepts of ophthalmic drug delivery with emphasis on the defense mechanisms, design considerations, and safety assessment of LEs for the ocular drug delivery.