Here is a list of some of the more common questions that patients ask us. There are obviously many issues to discuss relating to your eyes so if you need any further information, please contact us.
1) How much for a pair of single vision spectacles?
This depends on a number of things, namely:
- Your prescription: some prescriptions are made on request only, and therefore cost a little more. We need to know your prescription to give you accurate information.
- Whether you would like glass or plastic lenses?
- The coatings, tints and refractive index (or the thickness of the lens) you would like your glasses to have. It’s important to remember that there are huge variations in the quality of the anti-scratch coatings, the anti-reflex coatings and the photochromatic (lenses that go darker in direct sunlight) properties of a lens. As with all things, the more expensive it is, the better the quality.
- External factors like inflation or currency exchange rates.
- The frame you choose - obviously the more expensive your frame, the more expensive the glasses will be.
It’s a good idea to call us, or better still, pop in to one of our practices where we can advise you on all your options and discuss costs with you. We can help you choose the type of frame that would make your lenses look the thinnest and then discuss which lenses would best suit your eyes. (Remember, if you want to use your own frame, its shape, size and design can greatly influence your options and without actually seeing it we won’t be able to provide the best advice possible. First prize is to come in so we can help you out).
2) How much are bifocal spectacle lenses?
Refer to the above question as all the same things apply.
3) How much are multifocal spectacles lenses?
Again, see question one regarding coatings and tints. Multifocal lenses are more complicated as there are many different lenses all with a unique set of pros and cons. Your visual needs (for example, how much reading or computer work you do) and frame of choice will greatly affect the quote - call or pop in for more detailed advice.
4) Which is better: bifocal or multifocal spectacles?
It depends on your visual requirements – this will have to be analysed by one of our optometrists before any concrete advice can be given. As a rule, bifocals have a larger portion of the lens dedicated to the reading prescription than multifocal lenses do, but there is no intermediate distance prescription available in a bifocal lens. This is potentially a huge disadvantage. Multifocals have a gradient prescription in them, which gives you a distance, intermediate and reading prescription. The intermediate prescription of a multifocal is what is required to work on a PC screen. For this reason more and more people are using multifocals. Bifocals do not have this intermediate prescription. The type of prescription you have and your visual requirements (e.g. hobbies, computer work, iPad, etc.) need to be analysed in order to make the correct decision.
5) Are glass or plastic spectacle lenses better?
The answer really depends on what you need them to do. Plastic lenses are lighter and harder to break, but they scratch a little more easily than the glass ones do (we put a coating onto the lens which reduces this greatly). Glass lenses are significantly heavier and break more easily than the plastic ones do, but are more scratch resistant. Because glass breaks more easily than plastic, it is not advisable to use glass lenses for children wearing spectacles.
Most people choose to have plastic lenses these days because of the weight issue and the fact that they would prefer to have specs that are a little scratched but functional, than specs with a broken lens that are impossible to use. Transition lenses (go darker outside and virtually clear indoors) work a bit better in the plastic material as they change colour more quickly than the glass alternative.
6) If I wear glasses/contact lenses, will they make my eyes worse?
No they won’t; they only correct for an already existing refractive error. However, new research is being performed all the time and there is intense debate around this topic, so watch this space!
7) Which contact lens is the best?
This depends on the shape of your cornea, your prescription, your tolerance level to contact lenses, allergies, your occupation and your specific requirements from the contact lenses. There can also be significant environmental obstacles to wearing contact lenses (for example, dust, pollution, pollen counts, humidity of the air) We analyse all these things in fitting you with lenses and we’ll discuss your options with you.
8) Are hard contact lenses or soft contact lenses better for my eyes?
This depends on your prescription, corneal condition, presence of allergies and sensitivity to infections (to name only a few determining factors). There is some evidence suggesting that hard contact lenses slow down the regression of shortsightedness, whereas this doesn’t seem to occur with soft lenses. There are instances where hard lenses are the best option, for example, high prescriptions and corneal irregularity. Advances in soft contact lens designs mean they offer good vision for most patients. Hard lenses are generally more uncomfortable than soft lenses and it’s for this reason that most people choose to wear the soft ones.
9) What is astigmatism?
Any lens’s prescription comes from a few things, but principally that lens’s curvature. A lens has a front surface curvature and a back surface curvature. Imagine taking a round glass ball and cutting it in half. One side would be flat and the other uniformly curved – this is a stigmatic or spherical type lens. Now imagine cutting a glass rugby ball in half. Again, the back of one of these halves would be flat, but the front would be more curved along the horizontal meridian than the vertical meridian. A lens shaped like this would be called an astigmatic lens. Some people’s corneas are uniformly curved and so result in a ‘spherical’ prescription. Others have different curvatures, resulting in an astigmatic cornea and therefore an astigmatic spectacle prescription. Millions of people have astigmatism and it is generally straight forward to deal with. If it is irregular astigmatism (i.e. varying at varying positions on your cornea) it can become more challenging to treat. This irregular astigmatism is generally due to some form of pathology, but it can also be induced by trauma to the cornea.