Background: Cataract is a vision–impairing disease characterized by thickening of lens. The amount of incoming light is reduced due to cloudiness of lens that affects vision .The prophylactic measures are still great choice of treatment to prevent the onset and progression of cataract. The various epidemiological, nutritional, photochemical and genetic aspects are being studied to develop proper medical cure to mitigate the problem of cataract. The present study aimed to find out the serum electrolytes level in cataract patients in the tertiary care hospital in Bikaner , western rajasthan india. Material & Method: This study was conducted at Sardar Patel Medical College and associated hospital in Bikaner, Rajasthan from Dec 2018 to april 2019. There were 50 cases and 50 controls in the age groups from 25 to 75 years. Fresh samples were taken and required tests were performed following standard protocol. sodium and potassium level was estimated by backman coulter fully auto analyser. Result: The level of serum sodium was significantly high and serum potassium was found non significantly low in cataract patient. Conclusion: We concluded that, the increase serum sodium concentration affects sodium–potassium ATPase which may lead to cationic imbalance in lens which could result to cataract. So, a balanced diet with low sodium content can be a preventive factor for cataract.