Classroom Resource: Using NXT Light Sensor with EV3-G software
The NXT light sensor can be used with EV3-G, just not directly. Use the raw sensor block and the light sensor will give values between about 300-700. Missing are the wait for block, the loop block, and the switch block that use light sensor readings. If you need to use the the Wait For, Loop, and Switch blocks with the NXT Light Sensor you could also implement using the EV3 NXT Sound Sensor block. It sounds crazy to use the Sound Sensor block for the Light Sensor, but the the Sound Sensor block will turn on and off the NXT light sensor LED so you can measure both reflected light (dB mode with lamp on) and ambient light (dBa mode with lamp off). However, the measured range is scaled to about 17 (dark) to 70 (bright) instead of 0 - 100, so adjust your calibration and light thresholds accordingly!