Eyeglass prescription is the process of measuring the eye's refractive errors and prescribing appropriate glasses to correct vision problems and provide better vision. This examination is important to correct vision problems such as myopia (farsightedness), hypermetropia (nearsightedness), astigmatism, and presbyopia.
Steps to set glasses:
Eye examination:
Subjective refraction: The doctor uses a special instrument (phoropter) to change different lenses to fit your eye and asks you to tell which lens provides better vision.
Objective refraction: The refraction of your eye is measured by retinoscopy or autorefractometry. In these methods, special instruments are used to send light into the eye and measure how the eye refracts the light.
Measuring visual acuity:
The doctor measures how well your eyes can see with the Snellen chart or other visual acuity charts. These tables require you to read letters of different sizes.
Bifocal or multifocal lenses:
A doctor prescribes bifocal or multifocal lenses for people with presbyopia or other vision problems. These lenses provide both distance and near vision at the same time.
Lens material and frame selection:
The doctor advises on the material and frame of the spectacle lenses. Lens materials can be chosen from plastic, polycarbonate or high index materials. Frames are selected based on the user's face and preferences.
Additional tests:
Eye pressure (tonometry), fundus examination (ophthalmoscopy) and other tests can be performed to check the health of the eyes.
Glasses prescription:
An eye doctor writes a prescription for glasses to correct the refractive errors of your eyes. This recipe contains the following information:
Spherical (Sph): Indicates whether your eye is myopic (minus) or hyperopic (plus).
Cylindrical (Cyl): Indicates the degree of astigmatism.
Axis (Axis): Shows which axis the astigmatism is on.
Add: Indicates the degree of additional power required for presbyopia (for bifocal or multifocal lenses).
PD (Pupillary Distance): Indicates the distance between the pupils of the eye.
Eyeglasses should be fitted regularly, especially if you experience vision problems or are uncomfortable with your existing glasses. This is important for eye health and optimal vision.
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