Sticky/yellowish discharges.

Hello mummies. Im first time mummy. My son is 1month old, but on his right eye tends to have yellowish discharge that make him hard to open his eyes. Its so sticky . Any thing to recommend? Does putting few drop of breastmilk works? Or just go n see doctor instead. Everytime when he wakeups to drink milk he cant open his eyes due to the yellowish discharge. Lil bit worried about it.