Swift - How to detect one eye blink

I use CoreImage to detect eye blinking, it works fine except when I try to detect only one eye. Any ideas in how to detect eye contact flirting **by using CoreImage**?

    if let faceImage = CIImage(image: target) { 
        let accuracy = [CIDetectorAccuracy: CIDetectorAccuracyHigh]
        let faceDetector = CIDetector(ofType: CIDetectorTypeFace, context: nil, options: accuracy)
        let faces = faceDetector?.features(in: faceImage, options: [CIDetectorSmile:true, CIDetectorEyeBlink: true])
               
         if !faces!.isEmpty {
             for face in faces as! [CIFaceFeature] {
                 let leftEyeClosed = face.leftEyeClosed
                 let rightEyeClosed = face.rightEyeClosed
                 let blinking = face.rightEyeClosed && face.leftEyeClosed
                 let isSmiling = face.hasSmile
                       
                 print("isSmiling \(isSmiling)")
                 print("blinking \(blinking)")
                 print("rightEyeClosed \(rightEyeClosed)")
                 print("leftEyeClosed \(leftEyeClosed)\n\n")
             }
         } else {
             print("No faces found")
         }
    }

The properties hasLeftEyePosition and hasRightEyePosition are always true.

Both Eyes Closed

isSmiling false
blinking true
rightEyeClosed true
leftEyeClosed true

Both Eyes Opened

isSmiling false
blinking false
rightEyeClosed false
leftEyeClosed false

Left Eye Closed

isSmiling false
blinking false
rightEyeClosed false
leftEyeClosed false

Right Eye Closed

isSmiling false
blinking false
rightEyeClosed false
leftEyeClosed false