I'm currently working on a project involving (I think 3mm, 1.5VDC) Infrared LEDs. However, due to my photoresistor, I think the current, voltage, or whatever (forgot) will vary greatly to minuscule amounts. So, do these LEDs need UVLOs? They are very, very sensitive and I've already wasted half the pack.
LEDs are not damaged by low voltages.
If you are damaging LEDs, you must be driving them beyond their rated currents. Show your circuit to receive advice.
In general, very few electronic components are damaged by undervoltage. Some microprocessors can mis-execute in a brownout condition, which could have undesirable effects depending on the application. And Li-Ion batteries should not be discharged to too low a voltage.
LEDs cannot be damaged by "forward" voltages that are so low that they do not draw rated current.
They can be damaged by voltages that are low by normal standards.
LEDs are intended to be driven by either a constant current source of by a voltage source and a resistor such that. In both cases, maximum current is less than rated current.
In your circuit, worst case current must NEVER be able to exced maximum rated value.
LEDs may be damaged by reverse polarity voltage. Current drawn will be small, even when there is enough voltage to kill the LED.
Many LEDs are prone to electrostatic damage from "static electricity". Handling LEDs without wearing an earth strap or taking equivalent precautions may be enough.