the practice or profession of examining the eyes for visual defects and prescribing corrective lenses.
Questions tagged [optometry]
41 questions
9
votes
1 answer
Is eye patching effective for older children with amblyopia?
Parents of young children with amblyopia are often advised that vision in the weak eye can be improved by covering the healthy eye with an eye patch for a couple of hours every day. At what age does eye patching become less effective? Does the age…
StrongBad
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2
votes
2 answers
Why do optometrists "measure" your prescription with lenses orthogonal to the floor?
When optometrists measure your prescription, they use a machine that switches between different diopters. Except, the lenses on this machine are essentially parallel to the walls and orthogonal to the ground. Whereas, my ears are lower than my eyes,…
user3180
- 121
- 1
2
votes
0 answers
How are the parameters of an astigmatic lens prescription related to the geometry?
Given is spherical optical power, cylindrical optical power in diopters and cylindrical angle in degrees. Also given is the base curve in millimeters, and the contact lens diameter in millimeters. Also given
is the refractive index of the lens (and…
Emil
- 121
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1
vote
0 answers
Myopia advancing into Presbyopia and the Optics needed to correct them
This is a question about the optics needed to correct a hypothetical situation that everyone with Myopia will eventually encounter as they advance into older age.
Given that a person has Myopia and requires -2.00 diopters of vision correction, when…
user12711
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1
vote
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is a prescription +1.00 diopter lens the same as over-the-counter lens in +1.00 magnifying glasses?
is a prescription for +1.00 diopter lens to treat far sightedness the same optical correction as an over-the-counter +1.00 magnifying glasses? Or do the "magnifying" glasses actually magnify like a magnifier lenses does?
user12711
- 141
- 7
1
vote
2 answers
Based on the metrics of two glasses prescriptions, can I deduce values of an intermediary prescription
Say I have this glasses prescription:
OD -2.00 SPH +2.00 add 0.5 p.d. BD
OS -1.00 -0.50 x 180 +2.00 add 0.5 p.d. BU
And this prescription (values are fake):
OD -1.70 SPH +2.00 add 0.5 p.d. BD
OS -1.00 -0.50 x 180 …
Léon Pelletier
- 113
- 5
0
votes
1 answer
"SPH" Written in Cylinder section of prescription, along with no axis?
I found a glasses prescription, for the Cylindrical section, The left eye has a numerical value, but the right eye simply says: "SPH". Is this taken to mean, that the cylindrical for my right eye, is the same as the Spherical?
Also, AXIS is only…
Dylan
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0
votes
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Can corrective lenses be used to change the horizontal and vertical sizes of the images perceived by the eyes?
Given a condition in which each eye percieves the same image as slightly larger or smaller than the other in the horizonal or vertical direction - thus making it more difficult to combine the two into a single coherent image - can corrective lenses…
0
votes
1 answer
How do blue light filtering lenses work? Is it possible that they could they negatively impact your vision?
I have had some recent trouble with my vision and while trying to figure out what was going on one of the possible factors was a blue light reflective coating on my lenses. While that has been mostly ruled out at this point I am still curious about…
thesquaregroot
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