How effective is wearing PC lens to reduce eye strain helpful in addressing myopia?

PC lenses can mean several different things, but here I'm assuming you mean spectacle lenses that are marketed as being beneficial for people who view computer screens for long periods of time.

There are 2 important aspects to your question:

Firstly, in reality, there is little evidence to support the idea that special glasses (which may block blue light) help to reduce eye strain, especially for young people less than 40 years of age. 'Eye strain' is a vague, non-specific term that people usually take to mean eye discomfort or tiredness after looking at screens for long periods of time. The usual causes of this discomfort are dryness and possibly fatigue of the ciliary muscles of the eye which are responsible for helping the eye focus for near. The best way to reduce the impact of such over-use symptoms is simply to take regular breaks from looking at screens or reading and to use artificial tears as necessary to combat eye dryness.

Some time ago I wrote an answer here and explained that blue light from computer screens is actually not as bad as how it is often portrayed in the media.

The group of people who will benefit from customised glasses for computer viewing is actually older people with presbyopia / 'Lao Hua'. This is because presbyopia prevents the eyes from focusing at different distances, so when the presbyopia is bad enough some people may need a pair of glasses for far, a pair of glasses for computer use (medium distance) and a pair of glasses for reading the fine print (near distance).

With regard to the second aspect of whether there is any effect of PC lenses on addressing myopia, I think it is important first off to say a couple of things about myopia. Firstly, the exact mechanism that causes myopia to develop and get worse is not fully understood. Secondly, I am not sure what you mean by 'addressing myopia', but in general myopia cannot be reduced on a permanent basis with non-surgical ways. At most, we currently try to prevent myopia in children from progressing quickly. Current advice to slow myopia progression includes more outdoor activity every day. There is no evidence I am aware of that the commonly described PC lenses or blue-blocking lenses do anything to help stabilise myopia. Certainly, there is no connection between blue light exposure and myopia development or progression.

To recap, PC lenses are not necessary to reduce eye strain except in people with presbyopia/'Lao Hua', and there is no evidence that they help stabilise myopia. If you are worried about blue light, just dimming the screen using the computer controls, or using an inexpensive screen filter, will also cut down blue light reaching your eyes to a great extent.

There are many forms of spectacles that are touted to reduce eye strain, for example, when using the computer for a prolonged period of time. These forms of spectacles usually involve various anti-reflective lens coatings that reduce glare and improve contrast.

However, there is no evidence that they can be useful in preventing or slowing down the development of myopia in children. Unfortunately, these forms of spectacles definitely cannot reverse myopia in adults.

With respect to children and slowing the progression of myopia, only the use of Atropine eyedrops or Ortho-Keratology lenses has been shown to demonstrate efficacy in myopia prevention.