Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Jan. 01, 2021	Jan. 03, 2020	Dec. 28, 2018
Income Taxes [Line Items]
Income Tax Expense (Benefit)	$ 2,354,000	$ (1,022,000)	$ 1,671,000
Reversal of valuation allowance	495,000
Increase (Decrease) In Foreign Deferred Tax Liabilities	(213,000)	(46,000)	36,000
Income tax reconciliation of global intangible low-taxed income	$ 21,300,000	15,100,000	7,700,000
Income tax holiday, description	The Company utilized the high-tax exception to exclude income from foreign jurisdictions with foreign taxes at an effective rate that is higher than 90 percent of the applicable highest U.S. corporate tax rate.
Percentage of deduction in GILTI	50.00%
Deferred Tax Liabilities, Net	$ 4,844,000	3,810,000
Deferred Tax Assets, Net	4,722,000	3,750,000
Taxes Payable	4,650,000	2,572,000
Deferred tax assets, valuation allowance	42,502,000	37,007,000
Operating Loss Carryforwards	$ 152,863,000
Operating Loss Carry Forwards Expiration Term	expire in varying amounts between 2021 and 2037
Operating Loss Carryforwards, Limitations on Use	The California net operating loss carryforwards expire in varying amounts between 2028 and 2039
Operating losses and research and development credits carryforwards limitations on use	. In 2020, California enacted Assembly Bill 85 which imposed limits on the usability of California state net operating losses and research and development credits in tax years beginning after 2019 and before 2023.
Stock-based compensation	$ 3,277,000	2,859,000
STAAR Surgical AG
Income Taxes [Line Items]
Deferred Tax Liabilities, Net	222,000	658,000
Federal and State
Income Taxes [Line Items]
Deferred Tax Assets, Net	3,871,000	3,512,000
Federal
Income Taxes [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	573,000	3,003,000
Deferred tax assets, valuation allowance	34,681,000	30,308,000
Deferred tax asset, in foreign tax credits	2,013,000
State
Income Taxes [Line Items]
Deferred Tax Assets, Net	294,000
Valuation allowance, deferred tax asset, increase (decrease), amount	78,000	373,000
Deferred tax assets, valuation allowance	7,399,000	6,174,000
Swiss
Income Taxes [Line Items]
Deferred Tax Liabilities, Net	222,000	658,000
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries	1,295,000	1,295,000
JAPAN
Income Taxes [Line Items]
Deferred Tax Assets, Net	1,073,000	896,000
Stock-based compensation		$ 35,000	$ 46,000
US
Income Taxes [Line Items]
Deferred Tax Assets, Net	3,576,000
California
Income Taxes [Line Items]
Operating Loss Carryforwards	$ 27,275,000