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Doctor insights on: Visual Acuity

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Visual Acuity (Overview)

Visual acuity is the measure of the sharpness of vision. It is the most important measurement of eye function. In the us, the antiquated snellen visual acuity measurement is most often used. This is the "20/20" thing you have no doubt heard of.


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Can an ophthalmologist ballpark what the visual acuity of an eye is?

Can an ophthalmologist ballpark what the visual acuity of an eye is?

Yes: A well trained opthalmologist and optometrist will start fairly close on refraction based on their exam and use of the ophthalmoscope. Read more

Visual Acuity (Overview)

Visual acuity is the measure of the sharpness of vision. It is the most important measurement of eye function. In the us, the antiquated snellen visual acuity measurement is most often used. This is the "20/20" thing you have no doubt heard of.


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Can you tell me about what it means by visual acuity not exceeding 6/60 or 20/200 (snellen) in the better eye with correcting lenses?

Can you tell me about what it means by visual acuity not exceeding 6/60 or 20/200 (snellen) in the better eye with correcting lenses?

Lowered vision: The 20/200 line (6/60 in metric units) is usually the letters below the big "e" on the standard vision charts. This is also the level for legal blindness in most states. It is quite a lowering of vision and means that with the best eyeglass correction, only that level can be obtained. Read more

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How can you measure visual acuity w/ the snellen eye chart?

How can you measure visual acuity w/ the snellen eye chart?

Read smallest line: The snellen chart is a graded series of letters or numbers smaller as you go down. The uncorrected vision is the smallest line easily read with each eye. Your ophthalmologist will present you with lenses to improve the level of the smallest line to hopefully get you to 20/20 - the standard of normal. It is a subjective test requiring your active input. Read more

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Visual acuity. CC: OD 20/25-2. .. OS 20/30-2. .. intraocular pressure OD 21 OS 18. ..any interpretation or explanation for theses eye vision results?

Visual acuity. CC: OD 20/25-2. .. OS 20/30-2. .. intraocular pressure OD 21 OS 18. ..any interpretation or explanation for theses eye vision results?

Eye Exam: CC means with correct, like glasses or contact lenses. OD, right eye. OS, left eye. 20/25-2 means that you missed 2 letters on the 20/25 line on the vision chart. Intraocular pressure is the pressure inside your eyeball that keeps it from collapsing, similar to air pressure in your car tires. It is reported in mm Hg. Statistical normal is between 8 and 23. Read more

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I was wondering what does 6/5 visual acuity mean?

This is a metric: Measurement of vision. This would be a vision equivalent to 20/15 or better the 20/20. Read more

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Normal CT of brain within past six mths. Would a symptomatic brain tumor develop quickly since then? Also, normal eye exam and visual acuity tests

Normal CT of brain within past six mths. Would a symptomatic brain tumor develop quickly since then? Also, normal eye exam and visual acuity tests

Unlikely: Unless it is from somewhere else and it is infiltrating type to the tissues. Imagine a speck of tissue not seen six months ago by ct scan. The usual doubling time of a tumor in volume is 3 months. For it to grow and cause symptoms, it has to have been big enough to be seen 6 months ago. Read more

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What is a visual acuity test?

Visual acuity: Acuity tests are standardized charts of various sized objects, usually letters or numbers, which delineate the limits of vision. This can be with or without eyeglass correction. This number can then be used to compare your best vision to others or to legal standards such as the level needed to get a driver's license. It also is used by researchers testing ways to improve vision. Read more

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How can I know my visual acuity?

Compare to normal: You can get a rough idea if you have 20/20 by comparing your sight with someone who has perfect vision (or perfect with correction). Both of you view something at the limits of clarity (a sign far away) and if you both read it well, then you are 20/20. To determine lesser sight, you will need an eyechart and a proper lane. Read more

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How to find out my visual acuity?

Testing: You can get a rough idea if you have 20/20 by comparing your sight with someone who has perfect vision (or perfect with correction). Both of you view something at the limits of clarity (a sign far away) and if you both read it well, then you are 20/20. To determine lesser sight, you will need an eye chart and a proper lane. It is best to have an ophthalmologist measure it for you. Read more

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What's the highest visual acuity?

What's the highest visual acuity?

20/08: A number of younger people can see 20/15 and a few 20/10. I have not seen one at 20/08 but I have read about them. The highest acuity of all is in raptor birds (hawks, eagles, etc.) who can see down to 20/02 according to some accounts. Read more

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What is the world record for visual acuity?

Raptors: The sharpest vision that we know of occurs in the raptor group of birds (eagles, hawks, falcons) who have four times better acuity than humans. Visual charts in ophthalmologist offices start at 20/10 and a few can reach this point. I am sure there are some with 20/8 or so but the limit is the tight packing of the photoreceptors in the same size space. Read more

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What is combined visual acuity (combined vision)?

What is combined visual acuity (combined vision)?

Using both eyes: Combined visual acuity is the best that you can see with both eyes open. Though one would think that it can only be as good as the better seeing eye, often combined visual acuity is better than that. In other words, one can usually see better with both eyes open than with each eye individually. Read more

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I was wondering what does 6/5 visual acuity mean?

This is a metric: Measurement of vision. This would be a vision equivalent to 20/15 or better the 20/20. Read more

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What is the definition or description of: visual acuity?

Sharpness: Visual acuity is the measure of the sharpness of vision. It is the most important measurement of eye function. In the us, the antiquated snellen visual acuity measurement is most often used. This is the "20/20" thing you have no doubt heard of. Read more

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Is there a rough visual acuity test that I can easily perform?

On line: You can "Google" Snellen acuity chart to get a rough idea of the vision. You can also compare the limits of your vision with someones vision who has known acuity. At your age, I assume that you have a driver's license and most likely have had to pass an acuity test to get that license approved. Read more

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When documenting visual acuity rating what do the numbers mean?

Ratio: The ratio is an indirect way of measuring how small of an object can be resolved independent of the distance at which it is viewed. For snellen fractions (20/20 for example), the top number is represents the testing distance and the bottom number is an indirect measurement of the size of the object. Read more

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Is there a way to find out your visual acuity with an app or website?

Vision screening: A rough acuity can be gained from any number of apps/sites - search for vision/eye exam and follow the instructions. If you are wondering about reading glasses - go to a place that sells them and they usually have a chart you can read with different readers on. None of this is as good as good eye exam. Read more

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Does everyone have the same visual acuity versus light intensity response curve?

Does everyone have the same visual acuity versus light intensity response curve?

No: Evan an individual can vary in visual acuity range and light sensitivity function depending on the above factors plus genetic factors. So there likely will be some spread in the above between different individuals. Read more

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What is the difference of having a visual acuity of 20/10 versus a 20/50 vision?

20/10 great vision: A person who has 20/10 vision sees an object at 20 feet that someone with "average" vision will only see clearly at 10 feet (better than average vision). With 20/50 vision, in many states you are not legal to drive unless it can be corrected. In other words a person with 20/50 vision will see at 20 feet what a person with average vision will see at 50 feet (worse than average vision). Read more