Disaggregation of Sales, Geographic Sales and Product Sales - Additional Information (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 28, 2019 Country	Jun. 29, 2018	Jun. 28, 2019 Country Segment	Jun. 29, 2018	Dec. 28, 2018
Geographic and Product Data [Line Items]
Number of countries in which Company operates | Country	75		75
Number of operating segments | Segment			1
Sales Revenue, Net | Customer One [Member]
Geographic and Product Data [Line Items]
Concentration risk, percentage	49.00%	41.00%	43.00%	36.00%
Sales Revenue, Net | Geographic Concentration Risk [Member] | Other than China and Japan [Member] | Maximum
Geographic and Product Data [Line Items]
Concentration risk, percentage			10.00%
Sales Revenue, Net | Product Concentration Risk [Member] | Ophthalmic Surgical Product [Member]
Geographic and Product Data [Line Items]
Concentration risk, percentage			100.00%
Accounts Receivable [Member] | Customer One [Member]
Geographic and Product Data [Line Items]
Concentration risk, percentage			48.00%		37.00%