Most cases of myopia (nearsightness), involving progressively worsening vision, are largely due to inaccurate lens prescriptions and bad habits.
An optometrist or optician will have you sit with your head in the phoropter asking "better/worse" while flipping lenses - pretty much a binary search type of approach. But this is often done hastily and results in inaccurate prescriptions.

-----------

Unfortunately, inaccurate scripts are often inflicted upon children which as I will describe later, compounds into worsening vision over time, with the opticians/optometrists prescribing higher and higher power lenses that are only solving an issue that is created by the previous history of inaccuracy! Telltale signs of inaccurate scripts include:

- minor corrections

Eyes are not static objects and vision actually does vary from month to month, day to day, lighting conditions, blood pressure, etc. If a correction is minor, it's almost always unecessary and harmful.

- slightly different prescriptions for left (OS) and right (OR) eyes.

99.9% of folks have equivalent vision in both eyes. Like I said above, if a difference is minor, a correction would almost always be harmful.

- minor cylinder corrections (astigmatism.)

Astigmatism is extremely rare and when it does occur it's almost never minor. These corrections are especially egregious as they cause distortion compensation.

-----------

So why do eye professionals commit these cardinal acts of eye destruction upon their patients? Well we already discussed hastyness but that is clearly a vice that is going to result in bad outcomes in any profession.

What else? Well, eye professionals are taught to seek out as perfectly sharp an image as possible, and then back off the power a bit to reduce the possibility of eyestrain, headache, and dizziness. Some professionals don't even back off the power though..

In order to accomplish this task of perfect sharp vision, they add all of these minor corrections. When these ill-fitting lenses are worn for months on end, the body has a somatic response. The eyeballs elongate, which pushes the focal plane back, causing further myopia. [1]

The patient goes back to the eye doctor and now receives an even more incorrect script based on the transient state their eyes are in, induced by a cascading patterned history of harmful scripts.

In the worst case, the eye doctor recommends laser eye surgery which shaves the corneal lens of your eye into an artificial lens. Essentially, they carve your current harmful prescription straight into your eyeball. And then guess what happens? The eyeball shortens and often, the patients vision becomes progressively worse again. It can take months, but it does happen. [2] And now the fix that they recommend? More laser eye surgery. It's barbaric.

So please, do not get eye surgery before trying what I recommend below. Surgery on the cornea is advertised as non invasive but it can cause life long issues such as chronic dry eye. Please try to assess whether your vision is actually bad, or just a transient state due to a long history of bad prescriptions and poor habits.

----------

How do you break the cycle and restore your vision?

1) First, look at your current script. How asymmetric is it? How small are the cylinder values, if any?

Lower the scripts power and make the prescription symmetric. Remove the minor cylinder values. So for example, if you had -3.6 and -3.4 with some small astigmatism corrections, just ask for a script for -3.4 SPH in both eyes.

2) Make sure the pupillary distance is correct - eye professionals are notorious for fucking this up because the PD needs be to custom set for the frame the lenses will be going in, otherwise you'll have lenses with a focal center that is not aligned with the center of your eyeball. This causes distortion and uneven focus, causing eye strain and worsening vision.

3) Aspheric lenses - buy good lenses like Seiko double aspherics - just like cinema or photo lenses cost a lot of money because they reduce abberation and edge distortion, your eyes benefit from the same technology. Bottom dollar spherical lenses are okay, but strain is not healthy for eyes, and a good $300 set of Seiko transition lenses with coatings can last 10+ years. It's worth your eye health.

4) Have multiple pairs of spectacles. Use the weakest usable one (or no specs) depending on the task you are doing. For instance, I'm on my phone in bed, so I am not using any glasses. This will improve your vision over time. You can slowly reduce the power of your scripts if you care about it. I went from -4.75 to -3.5 and I'm happy with what I'm at, so I don't spend any effort trying to lower any further. But if you have the money, the time, and the will, you can get to -1.X territory through judicious use of a set of activity appropriate lenses.

Lastly, buy your own frame, buy your own pupilary distance tools, buy your own trial lens kit and trial frame like the Oculus UB6. Take time and figure out the right prescription for yourself without it being rushed. Test it and have it remade if the center of focus of the lenses is not at the center of your eyes. PD is integral!

-------------

An eye professional who cares and understands these things CAN help and even properly measure these values but they are rare. Sometimes if you want something done right, you kind of have to do it yourself. Or at the very least, guide or give your demands. After all, you are the paying customer.

Hope this helps others break the cycle of worsening vision. If anyone has any question, feel free to reach out.

[1] https://www.ncbi.nlm.nih.gov/books/NBK470669/
[2] https://www.webmd.com/eye-health/news/20030410/some-patients...