Business Segments - Schedule of Revenue Information by Product (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 28, 2024	Sep. 30, 2023	Sep. 28, 2024	Sep. 30, 2023
Entity Wide Information Revenue From External Customer [Line Items]
Total revenues		$ 11,581	$ 12,850	$ 35,973	$ 39,411
Cyclo G6
Entity Wide Information Revenue From External Customer [Line Items]
Total revenues		3,127	3,042	9,416	10,369
Retina
Entity Wide Information Revenue From External Customer [Line Items]
Total revenues		6,450	7,865	20,519	21,936
Other
Entity Wide Information Revenue From External Customer [Line Items]
Total revenues	[1]	$ 2,004	$ 1,943	$ 6,038	$ 7,106

[1] (1) Includes service contract revenues of $47 thousand and $0.4 million, and $0.4 million and $1.2 million recognized during the three and nine months ended September 28, 2024 and September 30, 2023, respectively. Includes $0.4 million and $1.1 million recognized revenue related to the exclusive distribution rights during both of the three and nine months ended September 28, 2024 and September 30, 2023, respectively. Other also includes revenues from paid service, royalty, freight and legacy G probes.