If you mean a Night lamp with low light meant to be used for sleeping time then it is not advisable for studying. It will cause mental and eye strain and may harm your eyes too. Even when you study using a ‘table lamp’ with sufficient light (moonlamps.info) the rest of the room should not be dark. It caused strain to me. Best would be to study in a tube lit room with uniform light.
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Should I study with a night lamp?