as u said ur having dark and light colour patches on ur face over many years.. i hope it is due to vitamin and iron deficiency
in ur diet due to may b heavy work or stress
it might not b directly due to phone and lappy usage but due to neglecting proper diet ..
i suggest u to take good diet full of vegetables and fruits and also multivitamin
tablet daily one for one month.. if yet not recovered get ur blood test
done for blood percentage..
i hope u wil get ur colour back soon..
all the best ..