Visiting an ophthalmologist is not an easy thing to do. There are several reasons for this, including visual problems, eye inflammation, eye pain and others. You go to the ophthalmologist for a medical consultation and an eye examination. After the examination, the eye specialist often prescribes glasses and/or contact lenses.
It is important for an optician to know how to read and understand the latter in order to adapt the frame perfectly to the correction and morphology. However, this task can quickly become esoteric for a private individual. It is then to facilitate you the task that we spin you all the secrets to decipher in no time, your ophtalmo prescription.
The presentation of an ophthalmological prescription
Like all prescriptions, the ophthalmic one has the same configuration. It is a paper subdivided into two main parts:
- header ;
- and the actual corrections.
Depending on the doctor's office, the presentation of these may vary. The document is either typed or handwritten, and in the latter case the handwriting should be sufficiently legible to facilitate reading.
The header of the order
This is the topmost part of the document. It contains different information about :
- The date ;
- The name of the practice or hospital ;
- The identity of the requesting doctor or service ;
- Patient's full name ;
The role of the header is to reassure the optician or pharmacist about the origin of the prescription. It is at the end of this part, from top to bottom, that the words "MEDICAL ORDER" appear. You may see some variations on other formats. In any case, it leads to the content of the prescription itself.
The prescription itself
This part contains all the treatments prescribed by the ophthalmologist for the management of your condition. Its presentation varies greatly from one health centre to another. It contains, among other things, the following information
- Names of medicines: these are trade names or International Nonproprietary Names (INNs). They are normally underlined when they are handwritten;
- The dosage form or presentation in the pharmacy ;
- Dosages: most are expressed in mg, some in percent;
- The quantity of each drug to be purchased ;
- Dosage: this is the way the treatment is taken. It is indicated on every prescription and carefully written down in as much detail as possible. Doctors often do this to ensure that patients understand.
In the particular case of glasses, the pattern is somewhat different. Here, the doctor prescribes only optical corrective lenses and adds all the additional information. These include:
- The type of lenses prescribed: single vision, depth of field or progressive lenses (sometimes tinted or therapeutic tinted lenses);
- The presence or absence of a frame;
- The characteristics of each eye for both distance and near vision: they are in numerical form with positive (+) or negative (-) signs;
- The bill ;
- The pupil distance.
According to the consumer law of 18 September 2014, the measurement of pupillary distance must be performed by the ophthalmologist and noted on the prescription. This makes it safe to buy corrective eyewear online. To find out more about the best online eyewear sites, see our feature.
It should be noted that at the end of all this information, the doctor signs it to certify its authenticity.
How to read and understand the prescription?
Reading a prescription focuses on the various prescriptions mentioned by the carer. It takes into account the nature of the prescription, which in turn depends on your disorder. A prescription for a simple medicine is therefore not read in the same way as a prescription for glasses.
Some common abbreviations
Very often, due to time constraints, doctors opt for abbreviations specific to the medical profession. These must be known in order to make the reading easier. These include :
- "VL": distance vision
- "VP": close-up vision
- "VI": intermediate vision
- "SPH": sphere
- "CYL": cylinder
- "ODG": right eye and left eye
- "OD": right eye
- "OG": left eye
- "Add": addition
- « PD » :Pupil distance or half pupil distance
Understanding your correction and visual defects
For prescriptions for optical lenses, the reading is completely different, because of the information that is present on the prescription. Let's take another typical example:
|PRESCRIPTION FOR GLASSES.|
A pair of glasses with frames
Right eye: +0.50 (-1.00) 20°.
Left eye: +0.50 (-1.50) 60
Addition : +2.00
Pupillary distance: 59.0
The prescription clearly states that it is a pair of glasses with frames. The lenses must be "progressive». Also known as multifocal lenses, progressive lenses correct a number of visual problems, particularly presbyopia. It is important for the doctor to specify the nature of the lenses, which depends on the type of vision problem the patient has.
What about the markings in front of each eye? These are the precise characteristics that each lens must have for each eye. They are worded as follows:
- +0.50 corresponds to the power of the eye expressed in dioptres. The sign (+) indicates hyperopia and the sign (-) indicates myopia ;
- (-1.50) and (+1.00) correspond to the value of the astigmatism for each eye;
- 20° and 60° : are the axis of astigmatism for the right and left eye respectively.
L’addition is additional information that corresponds to the measurement in dioptres of presbyopia (near vision). With regard to thepupillary distanceis the distance between the centre of each of your pupils. The health professional, i.e. the optician, will need to take the measurement of the half pupillary distance because most people are not perfectly symmetrical.
When purchasing glasses, it is advisable to give the prescription to the optician so that he can read it himself. This avoids possible mistakes that could disrupt the correction of the visual disorder. These specialists are well trained to understand every detail on the prescription. They will take them into account in order to provide you with the right glasses.
Astigmatism is a visual defect where your eye is not completely round.
Ideally, the eyeball is shaped like a perfectly round ball. Light enters it and bends evenly, allowing you to see clearly. However, if your eye is shaped like a rugby ball, the light bends more in one direction than in another. This means that only part of the object is in focus. Objects at a certain distance may appear blurred and distorted.
It is common to suffer from astigmatism at the same time as nearsightedness or farsightedness. These three conditions are called refractive errors because they affect the way your eyes bend (refract) light.
Astigmatism is fairly easy to correct by an ophthalmologist using glasses, lenses or surgery.
Symptoms of astigmatism may include the following:
- Blurred or distorted vision
- Eye strain
- Difficulty seeing at night
Do you find it difficult to see distant objects, such as motorway signs, until you are a few metres away, but you can easily read a book up close? It is likely that you are short-sighted. This is a fairly common condition that your eye doctor can usually correct with glasses, contact lenses or eye surgery.
The structure of your eye is the cause of myopia compared to normal vision. When your eyeball is too long or the cornea - the protective outer layer of your eye - is too curved, the light that enters your eye does not focus properly. Images focus in front of the retina, the light-sensitive part of your eye, instead of directly on the retina. This results in blurred vision. Doctors call this a refractive error.
Symptoms of myopia :
- the squinting of the eyes
- eye strain
- eye strain when trying to see objects more than a few metres away.
Short-sighted children often have difficulty reading the blackboard at school.
Hyperopia occurs when you can see distant objects better than close ones. Your eyes focus better on distant objects than on close ones.
Children with mild to moderate farsightedness can see both near and far without glasses, as the muscles and lens in their eyes can adapt very well and correct the farsightedness.
Causes of farsightedness
Your eyes focus light rays and send the image of what you are looking at to your brain. When you are farsighted, the light rays are not focused as they should be.
The cornea, the transparent outer layer of your eye, and the lens focus images directly onto the surface of your retina, which lines the back of your eye. If your eye is too short, or if the focusing power is too weak, the image will go to the wrong place, behind your retina. This is what makes things blurry.
Symptoms of hyperopia :
- difficulties in focusing on close objects;
- blurred vision
- eye strain
- Fatigue or headache after performing a close task, such as reading.
From your forties onwards, it becomes more difficult to see up close, but you can see very well at a distance. This is called presbyopia. Despite the name, it is not a disease. It is a natural part of the ageing process. And it is easy to correct.
Presbyopia is often confused with hyperopia, but the two are different. Presbyopia occurs when the lens of the eye loses its flexibility. Hyperopia is caused by a deformation of the eyeball that results in light rays not being focused properly once they have entered the eye.
You will notice these symptoms:
- you must hold your book, e-reader or laptop at arm's length;
- blurred vision at a normal reading distance;
- headaches or fatigue during close work.
How long is an opthalmic prescription valid?
- If you are under 16 years of age at the time of the consultation, the ophthalmological prescription is only valid for one year.
- If you are between 16 and 42 years old, the prescription is valid for 5 years. The optician may carry out an eye examination to check or adjust the correction if your eyesight has changed under the strict agreement of your optician.
- If you are over 42, the prescription is valid for 3 years.
The ophthalmologist may specify on the prescription for glasses that it is not renewable in the case of a specific medical follow-up.