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    What is meaning of +/- 4D in eye for job application requirement


    Puzzled about what +/- 4D in eye means for a job application requirement? Quickly get the answer from the expert responses below.

    Right eyesight and constant distance (sph -2, cyl -0.5, axis 10 ,v/a 6/9) and left eyesight (sph -2.25,cyl -0.50,axis 180 , v/a 6/9) - this is mentioned for the Forest Guard application. I wish to know then what is +/-4D? What does this mean?
  • #145282
    Your query is not very clear, but any way I will answer it as per my knowledge. The question and the image you have posted is mainly the reading of the spectacles. The reading what you have asked is commonly known as guinea pig in order to know the rapid and easy mammalian model. Guinea pig can be +/- 4D or +/- 2D lenses than is used in front of the eye for the duration between 10 to 5 days. This reading will be prescribed to an eye which needs to compensates for the imposed defocus by accelerating or slowing its elongation rate so that the eye becomes emmetropic with the lens in place. These types of problems are found in chicks, tree-shrews, marmosets and rhesus monkeys.

  • #145286
    This is a measurement of your eye sight. the power of spectacles to be used will be measured like + 1 or -1 like that. Probably for that forest officer job your power should not be more than +4 or -4. For many posts in government sector there will be a mention about eye sight.Probably for the mentioned post the limits may be +/- 4.
    I suggest you to contact a ophthalmologist and get your eyes tested and you can ask him about this question also. I think it is definitely a measure of your eye sight only.

    drrao
    always confident

  • #145290
    As for as I'm aware an opthalmologist or optimetrist report regarding eye assessment mainly includes whether one has

    1.Short sight : unable to clearly see objects at a distance
    2.Long sight : unable to clearly see objects closer to the eye
    3.Presbyopia: middle aged people (35-45 years) unable to read small letters or fine print at short distances, the same letters are clear when they move the object further away. If you notice your relative or teacher or friend trying to read an ID card or a customer copy of a credit/debti card, they try to focus correctly by moving the paper at an arm's length away from the eyes.

    These can be corrected by wearing glasses. I think here the word Dioptre comes in the picture. Dioptre or D is basically the power of the lens used to correct the vision.

    In simple terms when we use spectacles, it commonly has

    1. a concave lens is used to correct short sight .
    2. a convex glass lens is used to correct long sight.

    The common shortsight glasses or concave lens is usually denoted as MINUS (-1 D to -3D).
    The common longsight glasses or convex lens is usually denoted as PLUS (+1D to +3D).

    Hope this helps you. But i would suggest check with the forest department office who have advertised this so that you can produce a letter from an eye specialist as per the job specifications.

  • #145293
    The letter D (dioptre) is used for the power of eye lenses or glasses required to correct the eyes. For example a myopic person has to use ' - ' power lenses (concave) to correct his problem of not seeing far things clearly as he is able to see near but not far without glasses. On the other hand a person having hypermetropia can see at far but can not see near things clearly so he has to use ' + ' (convex) power lenses to correct for it.

    Generally people get hypermetropia with age and it so happens that if they already have myopia they have to use bifocal lenses or separate glasses one for reading and other for driving.

    Anyway coming to your question the requirement of +/- 4D for a job means that the eyesight of an applicant should not exceed these values that is +4D and -4D and in other words it means that in positive side the eyesight should not be weak more than +4D and the applicant should not require a power glass more than +4D. For example if he is using a spectacle of +4.25D in any of his eye he is not qualified.
    In the same way if he is using say -4.50D in any of his eye he is not qualified because -4.50D is more powerful than the limit of -4D.

    Due to certain requirements in forest department these limits are prescribed. Same thing is true in Railway department also. You have given the lense powers of your spectacle for your eyes (left and right) which are well within the prescribed limit so you do not have any issue regarding this.

    Knowledge is power.

  • #145298
    My answers are as under:-

    1. The common defects of eyes are:-
    (a) Short sight : When a person is unable to clearly see objects at a distance.
    (b) Long sight : When a person is unable to clearly see objects closer to the eyes.
    (c) Presbyopia: When middle-aged people are unable to read small letters at short distance.

    2. These defects can be corrected by wearing glasses. The letter 'D' stands for Dioptre. Dioptre or 'D' denotes power of the lens of the glasses used to rectify the vision. The limit for selection against the specific post is +/-4D. If the eyesight of any applicant is above +4D, then he/she is not eligible for the post. If it is less than -4D, again he/she is not eligible.

    3. You may get your eyesight checked from a reliable opthalmologist.

    Caution: Explosive. Handle with care.

  • #145300
    Generally in recruitment process eye sight is one important parameter and the applicant has to qualify it. Depending upon whether a person is having problem with seeing near objects or far object or all objects he is prescribed a spectacle after eye testing.
    The eye testing results tell us in quantitative terms as to how much power will be needed in the glasses to correct the eye vision of left eye and right eye individually.
    This power is measured in dioptre ( D) and depending upon near or far vision problem they come in + or - power.
    Normally on an average people wear glasses having powers in the range +/-0.25 to +/-3.5D but few people have power beyond that.
    In your job case they want that no candidate should have glass powers beyond +/-4D.
    It means those whose eyes are weaker than that they will be disqualified.
    You have given some powers in your question which it appears are the results of your eye test.
    If so they are within the powers mentioned in your job requirement condition of +/-4D. I think it is well within and OK.

    Thoughts exchanged is knowledge gained.

  • #145341
    You have mentioned your eyesight for the Forest Guard application is Right eyesight and constant distance (sph -2, cyl -0.5, axis 10 ,v/a 6/9) and left eyesight (sph -2.25,cyl -0.50,axis 180 , v/a 6/9.

    There are following standards description for different Medical classification :-
    1. A-1 Physically fit in all respects. Visual Standards —Distance Vision: 6/6,6/6 without glasses
    2. A-2 Physically fit in all respects. Visual Standards—Distance vision: 6/9,6/9 without glasses.
    3. A-3 Physically fit in all respects. Visual Standards—Distance Vision: 6/9,6/9 with or without glasses (power of lenses not to exceed 2D).
    4. B-1 Physically fit in all respects. Visual Standards — Distance Vision: 6/9,6/12 with or without glasses (power of lenses not to exceed 4D).
    5. B-2 Physically fit in all respects. Visual Standards — Distance Vision: 6/9,6/12 with or without glasses (power not to exceed 4D).
    6. C-1 Physically fit in all respects. Visual Standards — Distance Vision: 6/12, 6/18 with or without glasses.
    7. C-2 Physically fit in all respects. Visual Standards — Distance Vision: 6/12, Nil with or without glasses.

    In this D stand for dioptre. The eye power of the lens is measured in dioptre ( D) which is used to rectify the vision. .The + and - sign means that your eyesight is weak for far or near. +/- 4D in eye means that you eye sight must not be above +/- 4D


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