Brief Answer: Stage of cataract and structures behind lens Detailed Answer: Hi, Your father needs to get few investigations done before he goes on for cataract surgery (replacement of the natural opacified lens to artificial lens ) . Since diabetes affects the structures behind the lens, the doctor would look at the back of the lens called retina, vitreous and macula. If they are fine then he will get a 'go ahead' for cataract. They would also check the pressure in the front of the lens and if it is normal the surgery will be performed. Now cataract is at different stages, the doctors would normally operate before the cataract is matured and that gives better results than removed a mature lens. First know what stage is the cataract and get the examination done. Hope this answers.

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