Disaggregation of Sales, Geographic Sales and Product Sales - Net Sales by Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Oct. 01, 2021	Oct. 02, 2020
Product Information [Line Items]
Total other product sales	$ 4,199	$ 5,588	$ 11,582	$ 15,901
Total net sales	58,352	47,081	171,471	117,462
ICLs [Member]
Product Information [Line Items]
Revenue from contract with customer, excluding assessed tax	54,153	41,493	159,889	101,561
Cataract IOLs [Member]
Product Information [Line Items]
Total other product sales	2,525	3,325	9,324	9,880
Other surgical products [Member]
Product Information [Line Items]
Total other product sales	$ 1,674	$ 2,263	$ 2,258	$ 6,021