We thank Dr Daphne Han Chuk Yin for her feedback ("Iris can be altered by disease, injury, treatment"; Nov 12).
The Immigration and Checkpoints Authority (ICA) recognises that different personal biometric identifiers come with their own unique characteristics, as well as inherent limitations.
For instance, fingerprints can fade over time, while a person will also look different with age.
This is why it is important for the ICA to adopt a multi-modal approach to biometrics. The use of iris images complements existing identification methods using fingerprints and facial images, and will help strengthen the identification process.
For people whose iris images cannot be effectively scanned or enrolled due to disease or surgery, the ICA will rely on these other identifiers to verify their identity.
Brenda Tham (Ms)
Public and Internal Communications
Corporate Communications Division
Immigration and Checkpoints Authority