An apparatus and method for determining the distance from a distance-measuring-device to an object by sending a light-pulse from a light-emitting component toward the object by passing a current pulse through the component. A value based on the current or voltage across the component is used to determine the reference-time T0 when the value exceeds a first threshold-value, and determines first-time T1 when the value is reduced to a second threshold-value THL2. T1 is used to define two time-windows when intensity of reflected light is integrated to provide two values (Q1/Q3 and Q2/Q4) to determine a time of flight for the light-pulse based on the two values (Q1/Q3 and Q2/Q4), the difference between T0 and T1 (T1-T0), and the speed of light, c.