GLASS

Message of common value

WHAT IS CATARACT?

CLOUDING OF THE LENS

HOLIDAYS = LENSES

WHY DO YOU REGULAR NEED
EYE EXAMINATION WHEN YOU
HAVE GLAUCOMA?

YOU DON'T FEEL ANYTHING
BUT YOUR EYE CAN GET BLIND
SLOWLY
WHEN THE EYE PRESSURE
IS TO HIGH!

METAMORPHOSIS
(=curved lines)

THIS MAY INDICATE AGE
RELATED MACULA
DEGENERATION

ARE THERE...
DISCREET MAGNIFIERS?

YES, SUCH AS EASYPOCKET

YOU ONLY HAVE 2 EYES:

CHECK YEARLY !

SEE CLEARLY !

LENSES....
SO EASY !

SHOW YOUR EYES ...
WITH LENSES !!!

DAILIES: SAY IT WITH
YOUR EYES!

GLASS » GLASSES FOR MYOPIA CONTROL »

MYOPIE CONTROLE GLAS

MYOPIE CONTROLE

IS IT POSSIBLE TO INHIBIT MYOPIA WITH GLASSES ?

"Orthokeratology" treatment (short : ortho-K) showed the way:

For over 30 years, attempts have been made to adjust the cornea by fitting special hard lenses, which flatten (not deform ! ) the cornea. This reduced the power of the corneal lens : myopia correction. It was thought that this would work like orthodontic braces and that the treatment could be stopped after 1 or 2 years.  However, it turned out that a permanent treatment was needed like the night brace in orthodontics. So the "night lens" was invented, e.g. Coopervision's Dreamlite. Critics felt that the zone of flattening (= the optical zone) was actually too small, especially at the higher dioptres: (for -3, 3 mm of flattening was achieved. Knowing that laser treatment offers an optical zone of 6 to 6.5 mm, that seems little .   For -5, the optical zone was even smaller : Therefore, treating more than -5 did not seem possible.   Strangely enough, the children had little trouble with this.  Moreover, after some time the children with ortho K treatment appeared to become myopic less quickly (+- 50 % inhibition ) . The working hypothesis is the following.  The small optic area centrally gives good vision / the side of the cornea remains myopic of more than 2 dioptres ("myope defocus" ) and this was found to give inhibition of myopia ( explanation in the next paragraph ) .  So you see that every disadvantage (= small optical area ) can also have an advantage (myopia inhibition ).  However, night lenses must be closely monitored (must not cause any deformation) and must be replaced annually because the oxygen permeable material deforms after some time and no longer gives the correct flattening.

The working hypothesis of the Ortho k lens ("myope defocus") originated in myopia-inhibiting glasses and contact lenses, which recently came on the market and also give an inhibition of +- 50% :

Ortho K taught : Myopia is not just a too-long eye.  Better is : A myopic eye is too long centrally (= myopia ) but shorter laterally (= more normal ) . If you correct myopia with a normal eyeglass or contact lens , the image does arrive centrally on the retina but the image on the side of the retina falls behind the eye . So "farsightedness" on the side . Apparently the eye does not like that and the accommodation is tightened to make the side normal again so that the centre becomes nearsighted again .   This creates a vicious circle that leads to progressive myopia .  So to make a myopia inhibiting glass or lens, you have to manage to keep some myopia left ("a myope defocus") on the side of the retina

The first available myopia-inhibiting lens on this principle was "Miyosmart" from Hoya.     Very soon after came "Stellest" from Essilor .   By 2023, other brands were added in Europe, from which the same myopia inhibition (50%) can probably be expected.

Each type of myopia inhibiting glass has its own way of giving a myope defocus on the side :

Miyosmart - Hoya : +- 450 microlenses - Dims technology= defocus incorporated multiple segments
Stellest - Essilor : +-1021 microlenses - Halt technology = highly aspherical lenslet target
Myocare - Zeiss : - CARE technology = cylindrical annular refractive elements = alternative zones of defocus and correction zones
Mycon (stands for MY opie CON trol ) - Rodenstock - horizontal progression control: myope defocus of +2 nasal (= nasal side) and +2.5 temporal, based on the established anatomical asymmetry in the eye
Sight glass vision by Nikon/Coopervision: diffusion optics technology = thousands of micro dots, which gently scatter the light to reduce side contrast on the retina - not yet available in Belgium (but in the Netherlands and Israel)

The different lenses each have a different way of achieving myope defocus. The future will tell whether they are all equally efficient= +- 50% inhibition.

These lenses do cost +- twice as much as standard lenses : +- 390 € for a pair.  Most glasses do give the guarantee that if the myopia evolves 0.5 dioptres within the year, new glasses will be given for free

NOTE: what about photochromatic lenses

Several myopia inhibiting lenses exist in photochromatic version = discolouring with light.  This is useful when relatively high-dose atropine drops ( more than 0.05%) are also used.  Those children usually have light shyness because the pupil is also dilated by atropine, as a side effect.

NOTE: What about blue filters on glasses ?

Computer screens emit a lot of blue light.   This blue light is in the colour spectrum dcht to UV light and gives a bit more trouble ("blue hazard") . Blue light is also deflected more by the lens of the eye so that it is focused on the retina ("blue haze") .   Blue light filtering therefore gives more comfort for computer work but has no effect on myopia inhibition .  Blue light would be necessary for a good day and night rhythm ("the biological clock - controlled by melatonin) .  However, enough blue light still enters the eye not to disturb the biological clock.

What to think : The optometrists strongly believe in blue filters.  The eye doctor world is scientifically unconvinced of the importance.  However, blue filters are cool because they give a slight blue shine to the lenses . Otherwise, the lenses have a yellow-green shine, which is called "gold anti-reflection" .  This is perceived as less aesthetic.

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