NL7801906A - Contact lens of ground or moulded PMMA - has two larger curves at rim facilitating wearing - Google Patents

Contact lens of ground or moulded PMMA - has two larger curves at rim facilitating wearing

Info

Publication number
NL7801906A
NL7801906A NL7801906A NL7801906A NL7801906A NL 7801906 A NL7801906 A NL 7801906A NL 7801906 A NL7801906 A NL 7801906A NL 7801906 A NL7801906 A NL 7801906A NL 7801906 A NL7801906 A NL 7801906A
Authority
NL
Netherlands
Prior art keywords
curve
contact lens
radius
ground
pmma
Prior art date
Application number
NL7801906A
Other languages
Dutch (nl)
Other versions
NL168627C (en
NL168627B (en
Original Assignee
Hermanus Cornelis Limmen
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hermanus Cornelis Limmen filed Critical Hermanus Cornelis Limmen
Priority to NL7801906A priority Critical patent/NL168627C/en
Publication of NL7801906A publication Critical patent/NL7801906A/en
Publication of NL168627B publication Critical patent/NL168627B/en
Application granted granted Critical
Publication of NL168627C publication Critical patent/NL168627C/en

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
    • G02C7/00—Optical parts
    • G02C7/02—Lenses; Lens systems ; Methods of designing lenses
    • G02C7/04—Contact lenses for the eyes

Landscapes

  • Health & Medical Sciences (AREA)
  • Ophthalmology & Optometry (AREA)
  • Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Eyeglasses (AREA)

Abstract

The following characteristics are combined in a contact lens prepared from a hard material, esp. form polymethyl-methyacrylate:- a thickness at the centre of =0.09mm; a central optical zone of 7mm, with a spherical basic curve; and two concentric curves in the zoneof the outer rim, both of which have a larger radius than the basic curve with the outer curve having a larger radius than the inner curve. The dia. is pref. standardised at 8mm. The radius of the second curve is 1.5mm greater than the basic curve and the radius of the outermost, third curve is 12.5mm. Used to overcome the disadvantages of the soft material which are widely used at the present time for contact lenses. Whilst these can be made very thin, they are porous, so that optical fluids quickly cause deposits on them, and they age rapidly. On the other hand PMMA is highly transparent and resistant to ageing.
NL7801906A 1978-02-21 1978-02-21 CONTACT LENS. NL168627C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
NL7801906A NL168627C (en) 1978-02-21 1978-02-21 CONTACT LENS.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7801906A NL168627C (en) 1978-02-21 1978-02-21 CONTACT LENS.

Publications (3)

Publication Number Publication Date
NL7801906A true NL7801906A (en) 1979-08-23
NL168627B NL168627B (en) 1981-11-16
NL168627C NL168627C (en) 1982-04-16

Family

ID=19830365

Family Applications (1)

Application Number Title Priority Date Filing Date
NL7801906A NL168627C (en) 1978-02-21 1978-02-21 CONTACT LENS.

Country Status (1)

Country Link
NL (1) NL168627C (en)

Also Published As

Publication number Publication date
NL168627C (en) 1982-04-16
NL168627B (en) 1981-11-16

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Legal Events

Date Code Title Description
A1C A request for examination has been filed
AK Correction of former applications already laid open

Free format text: I.E.,DEEL 1 NR.17 VAN 10 SEPTEMBER 1979,BLZ.24,G02C7/04,7801906 C,GEMACHTIGDE MOET ZIJN:IR.A.J.VAN BUYTENE TE 2102 CL HEEMSTEDE

V1 Lapsed because of non-payment of the annual fee