I think the reason why Dutta's eyes are covered is so that initially he doesnt realise its Seema who is taking care of him and without realising that he would talk to Seema very politely and be grateful to her for saving his life.....she might even go to the extent of staying awake all night for him, etc.....he might also politely listen to her sad story without knowing he is listening to 'Seema's' story and he might develop a softcorner for this 'lady' who saved his life....he might even empathise with her fate of being in kotha .....
Seema might hide her identity from Dutta for the fear that he might get up and walk off in a bad physical condition if he comes to know Seema is the one who is taking care of him, so she might hide this fact till he is alright.....and she might also tell him stuff like 'I am suffering for what I did to someone long back....' and only in the end he will realise that this lady who saved his life, who took care of him very well, etc. is Seema 😲! And at that time since he would have developed a soft corner for this lady and is grateful to her for taking such good care of him, on realising she is Seema initially he might blast her and stuff, but eventually he might just show indifference and stop taking food and medicines, etc as a symbol of protest 😆.......and then eventually he will make peace with her and move on....to Nakku 😊.....