Disaggregation of Revenues, Geographic Sales and Product Sales - Net Sales by Products and Services (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 27, 2024	Dec. 29, 2023	Dec. 30, 2022
Product Information [Line Items]
Total other product sales		$ 1,358	$ 2,988	$ 14,679
Total net sales		313,901	322,415	284,391
ICLs [Member]
Product Information [Line Items]
Revenue from contract with customer, excluding assessed tax		312,543	319,427	269,712
Cataract IOLs [Member]
Product Information [Line Items]
Total other product sales		0	1,139	9,638
Other surgical products [Member]
Product Information [Line Items]
Total other product sales	[1]	$ 1,358	$ 1,849	$ 5,041

[1] Other surgical products include delivery systems and normal recurring sales adjustments such as sales return allowances.