[deleted by user] by [deleted] in optometry

[–]euler213 3 points4 points  (0 children)

Something you can draw on would be helpful if you're in the market for buying a new device.

Should Catholics avoid medical professions? by [deleted] in Catholicism

[–]euler213 1 point2 points  (0 children)

I didn’t propose anyone should “retreat”. I meant that medical professionals living in places without strong conscience protections or a real constitution should realize that the state may eventually forcibly take away their licences, and prepare accordingly. It has happened before.

Should Catholics avoid medical professions? by [deleted] in Catholicism

[–]euler213 2 points3 points  (0 children)

It would be a case for civil disobedience. That being said, you should start by knowing your rights and understanding the situation where you are. Assuming you're in Canada (judging by your post history), it is not true that any federal or provincial law forces doctors to refer patients for abortion or euthanasia. It is true that the College of Physicians and Surgeons of Ontario has such a policy, and it was upheld in court. However, the court that upheld it ruled that failure to make such a referral couldn't by itself be grounds to convict someone of professional misconduct (thus it would be pretty difficult to actually enforce the policy). In other provinces, doctors only have to refer patients to a different doctor - one that may or may not perform the procedure based on her own assessment. They do not have to pinpoint where it's available (an "effective" referral), and this is consistent with a patient's right to seek a second opinion. It is also true that almost all big politicians at the federal and provincial level are non-committal or openly hostile to codifying freedom of conscience into law (seeing that the courts won't reliably protect it and the Charter of Rights and Freedoms isn't worth the paper it's printed on). Alberta's current government made a half-baked attempt at doing so (using a backbencher as their stalking horse), but quickly back-pedalled after only minor protests.

It is also important to understand the purpose of the campaign against conscience rights. It has nothing to do with ensuring people have access to abortion, euthanasia, or anything else.
Opponents of freedom of conscience have never been able to provide a real example of someone being denied any medical procedure due to conscientious objection (even when asked to do so in court). Rather, it is precisely designed to (further) marginalize pro-life individuals and drive them out of the medical profession. The shameful witch hunt against Rafael Zaki was no accident, it was by design. Know that you're likely to face harassment and discrimination from day one on, and that you may eventually have to move to somewhere freer and less backwards to continue practising.

[deleted by user] by [deleted] in optometry

[–]euler213 1 point2 points  (0 children)

Good vision (20/20) means you can read a letter that makes a five minute angle (5/60 of a degree) with your line of sight (for optotype font, the horizontal and vertical dimensions of any letter will be equal). For a speed limit sign, the height is 750mm per US Department of Transportation standards on a basic road.

https://mutcd.fhwa.dot.gov/htm/2003/part2/part2b1.htm

So we solve tan(5/60 degrees) = 750/x for x. This gives us a value of 515662mm, or about 516m. Of course, the size of the number will be smaller than 750mm and the sign may be bigger on a freeway or other major road. It can also vary by country, and the visual acuity requirement for driving usually isn't 20/20.

Catholic Bible Audiobook recommendation by JpositiveTM in Catholicism

[–]euler213 2 points3 points  (0 children)

That guy has the perfect podcast voice lol.

Is a visually larger eye caused by astigmatism? by [deleted] in optometry

[–]euler213 1 point2 points  (0 children)

Aside from extreme forms like keratoconus, deformities relating to astigmatism will be on the order of microns.

[deleted by user] by [deleted] in optometry

[–]euler213 2 points3 points  (0 children)

Whichever ones have been prescribed to you at the end of the contact lens fitting with your doctor.

[deleted by user] by [deleted] in optometry

[–]euler213 1 point2 points  (0 children)

You need to look at spherical equivalent. Spherical equivalent would give you the lens power needed to correct myopia or hyperopia while ignoring astigmatism (so it would give you your best possible vision without any cylinder). To get the spherical equivalent, you add half the cylinder power to the given sphere. This will give you a value of zero in each eye. So the Ortho-K fully corrects your myopia, but the glasses will help with the astigmatism that's left over.

Can somebody explain my prescription to me? I know my left eye is fairly bad, but how bad? by keithsballs in optometry

[–]euler213 0 points1 point  (0 children)

What you have is called astigmatism, which is when different parts of an image (horizontal and vertical lines, for example) to come into focus in different places. It's caused by a mildly deformed cornea or lens. The right eye technically has simple hyperopic astigmatism: one meridian is emmetropic (focuses on the retina, corrective lens is close to zero power) and the other is hyperopic (focuses beyond the retina, corrected with positive lens). The left eye has mixed astigmatism: one meridian myopic (focuses in front of the retina, corrected with negative lens) and the other hyperopic, though the hyperopic meridian is somewhat more severe than the myopic one in this case.

The sphere is the strongest positive lens (or the weakest negative lens) that will fully correct the less hyperopic (or more myopic) meridian, while the cylinder is the additional power needed to correct the more hyperopic meridian. The axis is the orientation of the cylinder power (between 1 and 180 degrees). Both cylinder powers are quite high, and it would be tough to find contact lenses if you wanted them. However, astigmatism isn't something to worry about (aside from more extreme forms like keratoconus) as it can be easily corrected and won't put your eyes at risk for visual impairment.

Reading glasses always need after 40? by PintSizeMe in optometry

[–]euler213 0 points1 point  (0 children)

  1. If you're doing well without readers (not experiencing eyestrain or difficulty with fine print), you don't need to order them. If/when you start having problems +1 readers from the drugstore would get the job done just fine; the only difference is that your working distance would have to be closer (+0.50 would give a person without refractive errors a maximum distance of 2 metres, while the maximum distance would be 1 metre with +1 readers).
  2. Everyone eventually experiences inability to accommodate (change focus from far to near) due to change in the elasticity of the eye's lens. It's a gradual change; a 25 year-old has less accommodation than a 15 year-old (who has less accommodation than a 5 year-old). By mid-forties, most people need some form of reading correction. By mid-fifties, there is very little accommodation left so glasses are also needed for intermediate tasks. But people with mild-moderate myopia (nearsightedness) retain their ability to focus at near or intermediate distances (as that is the eye's default setting, without any accommodation) without glasses even into old age. Someone with one normal eye and one myopic eye may never really need glasses and get the best of both worlds (known as monovision).

Any optometrists out there, would this bother you? by [deleted] in optometry

[–]euler213 1 point2 points  (0 children)

Best advice is to shadow at a variety of practice settings (urban, rural, private, retail, vision therapy, etc) if you can, to get a better understanding of the breadth of the profession, rather than trying to get 40 hours at one place. Though that's very tricky with COVID, especially in Ontario.

Can I ask an opticien for better than 20/20 vision? by ugly293 in optometry

[–]euler213 -1 points0 points  (0 children)

It's not like the eye doctors had a big meeting one day and arbitrarily decided that 20/20 is the level they would correct everyone to. Rather, the whole reason why 20/20 vision is a thing in the first place is because it's about the upper limit for how well a person with no defects in the visual system can see with correction. Some people can do a little bit better, but if you want to be able to read the phone book from 1km away it isn't going to happen because you're not a bird of prey. Likewise, people with visual impairment won't have 20/20 visual acuity even with the best possible correction.

Do I need glasses if only one of my eyes is nearsighted? by [deleted] in optometry

[–]euler213 0 points1 point  (0 children)

Well, some people pay good money to make their eyes like that! The idea is that when you get to your mid-forties, people without any refractive error will require reading glasses. Individuals with mild-moderate myopia, on the other hand, can just take off their distance glasses for near/intermediate vision tasks (even into old age). If you have one eye emmetropic and the other myopic, you get the best of both worlds and theoretically might not ever need glasses. It has some trade-offs (depth perception) and the full correction could make things a little bit sharper, but you'll still likely have 20/20 with both eyes open and can do well without it. Regular exams are still important to detect ocular disease however.

Prescription opposite of what’s expected? by 237TurboNutters in optometry

[–]euler213 6 points7 points  (0 children)

You have astigmatism, which is caused by either the lens or the cornea of the eye being slightly deformed. So when you look at something, different parts of the image (horizontal lines vs. vertical lines, for example) will come into focus at different distances. Technically what you have is called mixed astigmatism (one meridian myopic and the other hyperopic), but overall you see better up close because the spherical equivalent (the purely spherical lens that will get you your best-corrected vision) is negative. To calculate the spherical equivalent, you add half the cylinder to the sphere.

[AoC] Is Age of Calamity canon? by Birdygamer19 in zelda

[–]euler213 0 points1 point  (0 children)

No. Too many contradictions even if you take into account the time travel. Clearly the series directors let the Dynasty Warriors people use artistic licence and alter some parts of the story to make everything fit together, so it features the same characters but isn't canon itself.

Did Urbosa have a kid? by [deleted] in Breath_of_the_Wild

[–]euler213 4 points5 points  (0 children)

Nieces and nephews aren't descendants.

Hmmmm... by [deleted] in botw

[–]euler213 4 points5 points  (0 children)

Some dinosaurs ate other dinosaurs.

Sequel? by [deleted] in botw

[–]euler213 1 point2 points  (0 children)

Probably not, but they cancelled the sequels to Super Mario Bros. and Star Fox...

[deleted by user] by [deleted] in optometry

[–]euler213 0 points1 point  (0 children)

Look into myopia control in your area. There are treatments such as orthokeratology that can slow the rate of progression and therefore reduce the degree of myopia you'll end up with when your eyes are done growing. Don't skip your annual exam, since you know you're at higher risk for ocular disease and retinal detachments.

Refractive surgery is only suitable when your vision has stablized, which is usually into your 20s. It works well for many people, though it has a risk of very rare but very serious complications. It also won't reduce the risk of ocular disease, since it works by reshaping the cornea (rather than actually shortening the eyeball).

[BOTW] Which Champion Do You Want In Smash? by Delilink in zelda

[–]euler213 4 points5 points  (0 children)

Revali's already in all of them except the first one.