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First of all, one has to distinguish between visual acuity (VA), which is a measure for the maximal possible resolution your eye-brain-system can achieve, and the refractive error, which measures the deviation of the optical system of your eye from emmetropy (=perfectly balanced optics, sharp focus on retina without any glasses) in diopters of spheres and ...


5

It is difficult to tell from that photograph what the pigmented area represents; a good photograph of the iris is hard to get without a slit-lamp (an instrument for close examination of the eyes.) Because irises are normally pigmented, they are subject to the same kinds of lesions as other pigmented tissue. The iris can have "freckles" (though not caused by ...


5

Some studies have shown that eye patching has been effective in adults. One study1 tested teenagers ages 13-17 and found that, combined with glasses and near vision activity, patching was effective in treating lazy eye. In fact there have been studies on treatment of amblyopia in older children/adults as early as 19572, but this study was only performed on ...


4

Questions 1-2 Unfortunately, the answer to these depend on the exact brand and line of contacts used. For example, here is a long list of silicon hydrogel lenses, and how long they last. Here is another list of materials used to make contact lenses (including many of the silicon hydrogel type). Some of those are dailies, but some can be worn day and night , ...


4

The information you provided Right lens Sph -0,50 Cyl -0,50 axis 10 Left Lens Sph -0,50 Cyl -0,50 axis 170 Type CR39 SN ARC is a little bit clearer than you can sometimes see. When you look at your prescription for eyeglasses, you can sometimes see numbers listed under the prefixes of OS and OD, or OU. They are Latin abbreviations: OS (oculus ...


3

The 0 to 1 scale is simply a decimal expression of the 20/20 (Imperial) or 6/6 (metric) measure of visual acuity. It's related to the smallest gap size someone can see on the Landolt C chart. Dioptres are not a measure of eyesight quality per se. Rather, they're a measure of the focal length of the lenses needed to bring your eyesight to normal. An ...


3

Most people will tolerate a visual acuity of up to 20/40 (being able to read something at 20 feet that a normal person with "perfect" vision can read at 40 feet) before seeing a physician. According to this article (https://www.ncbi.nlm.nih.gov/pubmed/16325714), patients over the age of 65 are more likely to tolerate this level of vision before seeking ...


3

A toric lens is the type that is used to treat astigmatism, not an aspheric lens. An aspheric lens is primarily designed to correct for the spherical aberration of the contact lens itself, the spherical aberration of the combination of the cornea and lens of the eye, or both. A toric lens is shaped like a slice of the side of a torus. It has a different ...


3

Partly the additional sizing information required for contacts (Diameter and curvature of the cornea are needed for contact lenses but not for glasses) and the power also changes because the physical distance between the eye and the lens is different. References: Here is a page explaining the differences between the two prescription types with explanation ...


3

You should not try to self diagnose an eye prescription. That being said, I'm going to partly disagree with the previous answer based on some technicalities. First, the process you describe is actually close to what real eye doctors use. They use a phoropter (machine with all the lenses) to test one prescription then test another. They keep going until ...


2

I have a magic number X. Take a guess what it could be? Is it 15? No, 15 is too high. Is it 12? No, 12 is too low. This leaves you with the mathematical average of 13.5, but that doesn’t help you because you don’t know wo how much too high and how much too low your other guesses were. What if we allow real numbers, and not only natural numbers? Then there ...


2

There are many different ways (proprietary methods) that these blue light coating are manufactured, but one general principle is called anti-reflection coatings. *I say "one general method" because hybrid methods can exist depending on the manufacturing company. Anti-reflection coating: The coating creates two reflections (on each side of the coating) ...


2

Note This answer is not a substitute for medical advice and medical advice questions are off-topic here. If you have concerns about your eyesight you must speak to your optometrist (or ophthalmologist if you are under their treatment). Question 1 - Can nearsightedness be just a result of eyes getting accustomed to working at very close distances most of ...


2

Generally, wearing the same pair of contact lenses longer then 6-12 months can cause increased risk of infection, as your biggest concern. Sleeping with contact lenses in has a similar risk, as contact lenses combined with closed eyes for 8 hours causes loss of oxygen to the Cornea. You're not losing much taking them out at night, and you're risking a lot ...


1

I found the answer: "CYL" in Spherical section, means no correction needed "SPH" in Cylindrical section, means no correction needed If AXIS is zero, that is shorthand way some O.D.'s use to write 180.


1

Although the tops of your ears maybe below the centre(s) of your eye(s) - you can have one ear lower than the other too - everyone is different. Some may find their ears are above the eye centres. When receiving your prescription made spectacles you should have them fitted (adjusted) to fit your specific shape. The link I provided shows adjustments and ...


1

In optometry, "Continuous Wear" of contact lenses is a term used to refer to FDA approval of a contact lenses for wear continuously up to 30 days, then removing them for at least a full night of rest. "Extended Wear" lenses are approved for wear by the FDA for up to two weeks. And "Daily Wear" are not approved for wear while sleeping. Lenses that are ...


1

From "Значение ретино-эпифизарной системы для психофармакологического эффекта" by Karen Ovanesov, who is co-author of one of those Russian articles on Pubmed to which you refer: (...) the visual perception is non-stationary in time and changes during the day. The use of stimulants of mental processes, such as caffeine can not only enhance the ...


1

A contact lenses fitting is more expensive than a standard vision examination for glasses. There are several reasons. The doctor (Optometrist or Ophthalmologist) must measure more perimeters of the eye than for glasses. And, they need to determine a material that performs well for the patient. Both soft contacts and hard contacts come in wide variety of ...


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