What is Presbyopia & why does it occur?
This is one of the first signs of ageing. 🙄 Joy!
The crystalline lens of the eye is like a zoom lens in a camera, able to focus close up & re- focus on the distance, repeating continuously. This lens grows denser throughout life reducing its flexibility & manifests as an inability to focus as quickly initially, to not being able to focus as close, ultimately requiring a presbyopic correction i.e. reading glasses. This is presbyopia and 1st signs appear around 45 years of age.
Why do I require Varifocals?
Whether you have a short sighted (myopia) or hyperopia (long sighted) prescription you will require a reading correction at some point.
For short sighted (myopic) persons you may just take your glasses off to allow you to read but this may be impractical. If you wish hands free vision Varifocals offers both myopic & hyperopic the opportunity to correct both distance, intermediate & near vision problems with one pair of glasses.
What are varifocal lenses?
Also known as progressive spectacle lenses or progressive addition lenses (PAL) Varifocal lenses are corrective lenses used in spectacles to correct presbyopia and other disorders of accommodation.
They are characterised by a gradient of increasing lens power, added to the wearer's correction for distance prescription (refractive error)
The gradient starts at the wearer's distance prescription, at the top of the lens and reaches the full reading power, at the bottom of the lens. In practice this should allow clear point of focus to see objects at any distance.
Difference between Bifocal & Varifocal Lenses?
Bifocals have two separate zones for distance and near vision, it is easy to locate and spot both parts with a clear visible distinguishing line. The upper part of the bifocal lens is for distant vision and the lower portion is for near vision.There is no intermediate correction i.e. for computer screens, arms length distances. You will always notice the differentiating (bifocal) line when switching from far to near.
Visually, bifocal glasses show off your age and tell others that you wear reading glasses, its not that problematic if you prefer showing your age but sadly not everyone wants to tell the other person his age through their lenses.
On the other hand, varifocals do not display any such distinguishing factors. Moreover, the varifocals are divided into three parts for correcting near, distance and intermediate vision defects. The upper part of the varifocal lens corrects your distant vision, the intermediate is for computer work like reading an article online and the near portion is for distant vision. Unlike Bifocals, wherein there is a quick move from distant vision area to the reading area. When it comes to varifocals, there is a very smooth transition from one zone of power strength to the other.
Cost of Varifocals vs Bifocals
Bifocal Lenses. Been around since 1760 .Old Tech. Varifocals first showed up 200 years later!
There are many types of varifocals & a huge variation in price between different brands & designs given out by various optical retailers which can be baffling!
Varifocal glasses combine the benefits of both convex and concave lenses to correct myopia and hypermetropia in a single lens. The upper portion of these advanced glasses allows the user to view distant objects clearly, while the lower zone of the glasses let the user view close by objects. Thus, the user may feel difficulty in viewing from these double prescription glasses. It is very normal to experience distorted vision. Usually, the peripheral vision is affected along with difficulty in analysing depth perception. People may experience a little trouble while climbing the stairs, driving or walking on the footpath.
First time varifocal wearers may take more time to adapt. Whilst some put them on and have no issues adapting most take a few weeks to adapt from the change in head & eye movements- after all you are changing habits of a lifetime!
Like most product purchases you tend to get quality in line with how much you pay for it. You could get on famously with a £100 pair of good varifocals but with more expensive ones you will generally get less distortion in the periphery; wider clear areas for distance ,intermediate & near zones.
The way I look at it is, if you wear glasses full time, change them every 2 years & they cost you e.g. £365 then it costs you 50p/day ... for something you wear all day every day for 2 years!
TIPS for adapting to varifocals
Time: Adjusting to new varifocals requires some time and it is the only way to overcome the issues that are associated with the new prescription glasses. You need to give ample time to your brain as well as the eyes to focus and become habitual to the new varifocals.
Wear full time: Wear your glasses, varifocals all the time and you will feel your eyes are adjusting quicker.
Avoid your previous pair: Two steps forwards, one step back. You are well adapted to these already. Like worn shoes, they may feel more comfortable than the new ones but after a period the new ones will feel just as comfortable.
Buy Good (Digital Freeform) Varifocals
Conventional Varifocals Digital Freeform Varifocals
Coventional varifocals do not account for the eye movement dynamics.This means power can vary in different eye gaze directions.
With Freeform lenses:
Every point in the lens is adapted to the individual’s eyes
Entire lens is of the correct prescription
Superior optical quality. HD vision
Progressive lenses achieve optimum vision in the far (including lateral far), intermediate and near regions.
Opt for advanced coatings: Digitally advanced glasses have become a necessity in today’s world to protect eyes from blue light, glares, reflections and UV rays. For those who work on computers for extended hours or similar digital screen devices, it is highly recommended to use lenses with blue light blocking features along with the anti-glare coating.
At Glasses Outlet we use HOYA digital freeform lenses. Hoya's anti-reflective, blue control coatings come with a 2 year manufacturer's protection against coating defects.