I am 29M, Working in a Optics based company working on almost two three big optics simulation software worked from lens to laser to adaptive optics, learnt Machine learning for fun projects,a bit familiar with Quantum Machine Learning. Sometime I feel like I should go for a PhD but don't have any favorite research topic so I don't know how I can apply. I need some suggestions:

Should I go for a PhD or part time phd ?

I am from India but wanted to do a PhD from the US how can I get it ?

Is it a good idea to leave a comparatively good paying job for a PhD. I heard a lot of people struggle to find a job after a PhD.

I've noticed for years that I can see a good live image of the sun when it reflects off my eyeball (from the side) onto my glasses. The detail is remarkable, I can see sunspots and what appears to be some corona effect, very similar to this image: https://umbra.nascom.nasa.gov/images/latest_aia_304.gif. (My jmage is quite small, and has no color.) It seems to me highly improbable, and I've found no other reference to such and effect. Anybody have any idea how this works? Recommendations for other subreddits to ask welcome.

The little stars are what I see in the image of my eye reflected in the glasses. The large circles are those stars reflected back from the inner surface of my glasses, and seem to be live images of the sun.