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Can you tell me what is "+" and "-" specs number?
Date: 28 Jan 2012 Posted By: Paresh Gujarati
Group: Opinion About Category: Miscellaneous
Can you tell me what is "+" and "-" specs number? I have following number regarding specs in my eyes. Left eye is having Cylinder no. of -1.00 and -145 axis and in Right eye +1.00 is cylinder no and +100 is axis. What does this cylinder and spherical no means? What does this axis mean? What is the meaning of + and - no. in eye? Does - means no. for far sightedness and + for near sightedness? Does these numbers can be curable by surgery? In what cases it does not operated and in which cases results can be negative?
|Author: Askush 28 Jan 2012 Member Level: Gold Points : 4 (Rs 2) Voting Score: 0|
The above data is used for constructing the lenses suitable for curing the defect in vision. Since you are having numbers in terms of cylinders that means you are suffering from defect called 'Astigmatism' in which the person can't focus on the object clearly because he or she see image in different axis. The two axes are vertical and horizontal. So for curing the problem we use the cylindrical lenses. We have plus cylinder notation and minus cylinder notation. In plus cylinder notation which includes two notation one of sphere and other of cylinder. The sphere component is lonely used to treat the near sightedness or long sightedness.
Now for your Right eye which has +1.00 for cylinder and +100 axis, which means it have plus cylinder notation. According to this the cylinder power is more convergent then the sphere power. For your left eye which has -1.45 and -140 axis means that you're this eye has minus cylinder notation which means the cylinder power is more divergent then the sphere power. The meaning of axis is that it defines the position of sphere and cylinder. The lens for the astigmatism patient is made of both sphere and cylindrical combinations.
For more information you can go through the profile of me, where you will find article about the working theory of these glasses.
|Author: Dr Sachine (Eye Retina Surgeon) 28 Jan 2012 Member Level: Gold Points : 7 (Rs 6) Voting Score: 0|
Refractive errors are very common in general public & regular screening of children should be done at schools
"+" power spects are used to correct hyperopia (far sightedness). Person with hyperopia can't see near objects clearly. So he needs glasses.
"-" power spects are used to correct myopia sightedness). Person with myopia can't see far objects clearly. So he needs glasses.
Myopia is much more common than hyperopia. Myopics have more chances of developing retina problems like retina detachment. Myopics may have very high power even up to -20 or -30D while hyperopcs generally have power up to +3 or +4D
Cylinder is needed for people who have astigmatism. In such people, corneal curvature is not regular in all parts. Cornea is either too steep or flat in certain axes. Axis indicates this meridien where its too steep or too flat. So cylinder (either + or -) is placed in front of eye to correct the power in particular axis to give clear image. A person can have + cyl. in 1 eye & - cyl in other eye.
Surgery to remove spects power is called refractive surgery. Various techniques are available- LASIK (laser induced keratomileusis), zyoptics, etc. This surgery is done after completing 18 years of age once spects power stabilizes
. Read more-
LASIK - Laser eye surgery to reduce glass power -Advantages, cost, side effects
LASIK & Zyoptics To Remove Glass Power
Another option to correct such error is contact lens. Soft contact lens are very useful. Toric contact lens is used to correct astigmatism
. Read more-
Contact lens- Advantages, disavantages & precautions to avoid side effects
|Author: Manaswini.K 28 Jan 2012 Member Level: Bronze Points : 5 (Rs 2) Voting Score: -1|
To know anything in detail we need measurement. And measuring the eye sight that is the defect in your eye, there is a method. There are many types of defects for an eye like :
1. Short sight
2. Long sight
The two basic eye defects are Short sight and long sight
Short sight : Short sight is an eye defect where a person cannot see the distant objects clearly. The amount of blurriness indicates the sight of the eye. It is usually denoted by the negative sign i.e minus sign or "-"sign. The higher number with a negative sign indicates more amount of eye defect i.e. -3 is more defective than -2 power. Spectacles are used for correcting the defective eye sight. This type of defective eye sight is observed in children or young age people. The eye sight becomes constant i.e. it does not change once the person reaches 18 years of age. These days high quality contact lenses are also used for cosmetic purposes since most of them do not prefer wearing spectacles in public due to beauty reasons. Other surgeries like laser surgeries are also in vogue these days which id done for people who are above 21 years of age!
Long sight : This is the type of eye defect generally seen in old age people who are above 40 years of age. This is the inability to see nearer objects. Reading glasses are used generally to correct this type eye defect. Surgeries are not recommended usually. The reading glasses power is denoted with the power "+" or with a positive sign. Higher the positive power,higher is the eye defect!
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