I am still trying to wrap my head around higher order aberrations, which are essentially a more specific way to describe ‘irregular astigmatism’. More specifically what effects they actually have on ones functional vision in the DAY time and Night time.
The obvious: At night, the typical HOA’s: Halo/Starburst’s. Most common (because it is so easily described by patients).
The *should be more obvious* — When you look into the way our eyes work, the normal refraction,.. that everyone has some level of HOA’s.. some more than others and so on. Then take into account those with a high level of HOA (especially people who have not had eye surgery) – you have to think what kind of effect does it have on vision all the time?
The light is refracted and focused/converges much less than optimally. In fact, the worse the HOA’s , in the right spots, the more scattered the incoming light is across the retina. You have light focused where it should be for a clear image, but also some percent of it scattered depending on the corneal surface (or lense surface if it exists there as well).
Point being, is the effects of problematic HOA’s don’t just turn on at night time,.. or when the pupil is dilated.
True, the larger the zone of light entering, the more likely to have error present. Though if the HOA is present across the entire central vision then it is going to be present at all light levels and times of day.
Other than halo’s and starbursts.
From what I read on optics, it seems that it is quite common to have problems with contrast, vision can seem foggy, along with colors being presented improperly from a well focused zone.
I don’t know how much optometrists study or are presented with HOA’s in school, (probably more now than before) , but I imagine it isn’t a foreign concept even if it is just now being something that is treatable and more easily diagnosed via wavefront. Nonetheless what types of visual distortion could be imagined based on high levels of HOA’s?
I am particularly interested in this because of my own HOA with 20/20 (slightly better) vision, without any optical correction — with no ‘regular’ astigmatism. (Or any lasik or other eye surgery in my lifetime, being 30yrs old *this only being problematic in the past 3 years give or take) — Previous vision was always absolutely perfect in hue, contrast, acuity, light sensitivity, and all the factors I took for granted.
Now my visual acuity suffers a little because of the aberrations, but a Snellen chart will still read 20/16 for me.
However I have the pronounced Halo’s and Starbursts on any point of light at night.. and even in daytime. Colors don’t seem dim like a cataract, as I don’t have any sign of it. But they are almost ‘too’ vibrant. Orange street signs seem a few hues brighter than they used to for example. This holds true with all colors across the spectrum to some extent, some more annoying and noticable than others.
With the majority of cars having Daytime running headlights these days, every on-coming car on a sunny day is a slight starburst and the light is something you instinctively want to turn away from (but can’t obviously).
Is it because of the defocus of incoming light that points of light seem ‘brighter’ than they used to? Does that make sense? That even though the light is no longer one single point like it should be, it is now a bit ’starlike’ it is brighter and has more ‘glare’ ?
Also does it make sense in optical terms that due to the improper bending that even colors/hues and such would seem different.. but not ‘dim’?
I know this detail is all over the place — but for anyone who understands optics.. whether you are an astonomer or eye doctor, would you mind commenting, to the best of your knowledge, how this would effect someone like me? Just in general, take a high level of *Higher order aberration* in a normal healthy eye, that doesn’t need 1st or 2nd order correction.. that as I mentioned has presented with these symptoms in the late 20’s.
All I generally find on the internet is post-lasik reports, which is similar but not exact as my eye is untouched.
Not looking for treatment or cures here — as I know it seems my best shot at treatment is/are RGP contacts, with possibly lenses custom made for my wavefront.
I’m just trying to understand better (and slowly I am.. as optics is very complex) what is going on with my vision as I am so used to perfect (to me) vision.. and now it is just ‘weird’.
Again, thanks for reading if you have done so — and your opinions on the matter are of immense interest to me, personally.
Thank you,
Your question is really complexed, and i doubt many people will be able to respond. I’m not sure if the problems you’re describing is completely due to higher order astigmatism. Typically, comas, tetrafoil, and other Zernike Polynormial abberation will decrease your VAs more than the other qualities you’ve mentioned. The concept is that the higher order astigmatism dont effect your vision too much. They’ve developed intraocular lenses that have corrected most of it, and people have reported an acuity of 20/13.
The halos and change in color sounds more of a lens problems to me. Usually, the yellowing of the lens will cause an increase in the scattering of light, and decreased overall contrast (although certain colors will seem more vibrant than others based on relativity.)
Your question is all over the place. If you can filter out all the "what i know" part and just focus on your question.. people can answer your question more effectively.
This is my personal video log of when I got Intralase Lasik Wavefront Laser Eye Surgery. I did not know what to expect and I was willing to take the risk. I just new I had to document my experience and share it with others.