Blindness is the condition of poor visual perception. Blindness is strictly defined as the state of being totally sightless in both eyes. A completely blind individual is unable to see at all . Visual impairment can limit people’s ability to perform everyday tasks and can affect their quality of life and ability to interact with the surrounding world. Most of the diseases and conditions causing visual impairment and blindness can be prevented or readily treated with known and cost-effective interventions. However, refractive error as a cause of visual impairment was not included, which implies that the actual global magnitude of visual impairment is greater.