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For eye care professionals

The story of how we created record breaking -108D lenses for photographer, Mr Miskovic

01 June 2017

Discover a video testimonial of Mr Miskovic and his optician. It contains all the steps taken by the optician to adapt the -108D cyl 6.00 lenses from the eye exam, the frame choice, the...

Watch Mr. Miskovic's story


 
 

For many years Essilor’s SL Lab (Special Lenses Laboratory) has been developing a recognised expertise in the manufacturing of Special Lenses. Consequently, SL Lab has been naturally solicited to manufacture a pair of lenses with -108DS, 6.00 cylinder, biconcave with double asymmetrical convex facet for Mr Miskovic, a Slovak wearer suffering from a severe myopia and keratoconus. 

The new lens design required significant expertise.

 

The SL Lab team worked together to manufacture these very powerful lenses. SL Lab opted for a high index mineral material (1.807) with optimal optic specifications for such power. The lenses were made possible through the use of the SLS calculator which was specifically designed to meet the needs of Special Lenses designs and manufacturing. A cutting tool was also specially designed to manually perform machining, polishing and fining the optical zone.
 

A concentration of calculations, technology and expertise for outstanding equipment

 

The internal face of the lens has been designed with a power of -77D and an optical aperture of 18mm diameter to give the wearer a comfortable field of vision. The +2.50D curved convex side was roughened to absorb light-made reflections reflected on the inside of the lens ensuring wearing comfort is improved.

The additional correction was made on the front surface with a power of -31D associated with a 6.00D cylinder with an inverted core axis in order to create a perfectly round optical aperture of 24mm diameter.  This optical aperture allows the wearer to benefit from about +/-30 degrees field of vision, which is gratifying considering the lens power. A convex facet of a camber +6.00D was chosen not only to thin the lens but also to allow for improved glazing and an ideal vertex distance. Finally, a Superdiafal anti-reflection coating was applied on the front surface of the lens to improve wearer comfort.
 

An exceptional quality control

 

The Lens power was checked with a radiuscope, an optical measuring device for principal rays of a torical or spherical optical face, it is the only device capable of measuring such power.
 

A grateful and satisfied wearer

 

The lenses were cut and glazed successfully into the frame chosen.  Mr Miskovic revealed that his vision quality has improved, gaining clarity with a wider vision field. His new acuity is evaluated today at 1/10 compared to his previous acuity*.

 
* Mr Miskovic has previously been dispensed lenses of -104D 6.00 Cyl, by the SL Lab in January 2015, giving a 1/10 acuity. His vision has gradually deteriorated to 1/20 a year later, due to his visual condition.

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