My Player keeps rolling 1's

I know the dice roller is perfectly random but I have seen my player roll 1's as often as 7 times in a row. and they rarely roll above an 8. I am not sure what to do since it is just purely there luck. but it is really souring the mood at the table. I am open to advice  System is 5E 

Hi Doll Face! Yeah, I had a player roll seven 1s last night as well (though not in a row). It happens. :/ Two suggestions off the top of my head: 1) check their character sheet . It's possible that some information is misentered. We have had a couple of cases where we had weapon damage rolls continually being "1" because a formula was entered incorrectly.  2) Institute some kind of "Karmic Dice" rule. After a certain number of bad rolls, a player gets Inspiration, or their next hit is a free critical, or each 1 rolled is a cumulative +1 modifier to following rolls until a roll succeeds, or some kind of benefit.