Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Unvested early exercised stock options	$ 16,187	$ 8
Payroll related costs	11,675	7,895
Optical laboratory and inventory costs	9,874	1,032
Marketing expenses	6,070	9,585
Charitable contribution	4,738	5,182
Other accrued expenses	15,112	10,568
Total accrued expenses	$ 63,656	$ 34,270