BENGALURU: Senior citizens and children younger than five years wanting to register with Ayushman Bharat-Arogya Karnataka (AB-ArK) are facing problems with their Aadhaar authentication failing due to fingerprint issues. This has prompted the government to ask card-issuing agencies to deploy iris scanners approved by the Unique Identification Authority of India.While the shrinking of the subcutaneous fat in fingers and fading lines create problems in case of senior citizens, lines in children below five years change as they grow.The problem is being seen in one in every 100 people seeking registration, health department officials said. Wary of biometric authentication failure increasing in coming days, the government has decided to deploy Iris scanners at all community health centres and taluk and district hospitals."Fingerprint is a basic biometric authentication marker, but among many senior citizens the fine lines on the finger would fade out over the years. This is noticed at the registration level itself," said Dr BR Venkateshaiah, medical superintendent, KC General Hospital. The problem is evident among those who had done their Aadhaar registration 7-8 years ago.In such cases, officers try to authenticate the individual's Aadhaar through OTP, but this mode too is fraught with problems as he or she may not be using the same number. Officials also recall that National Informatics Department had foreseen the problem and suggested using iris scanners instead. A January 4 circular mandating the procurement of Iris scanners within January 31 has also capped the cost of each scanner at Rs 12,500.