Modern Equipment
Our laboratories are equipped with high-precision measuring instruments to carry out investigations regarding contact lenses and intraocular lenses of different types and accuracy. The high reproducibility of the results is ensured by regular checking and calibration.
Accuracy
The determination of different contact lens and intraocular lens parameters and regular control serves the purpose of quality assurance, checking functionality of a product and the safety of the end user.
Contact Lenses, Intraocular Lenses, Spectacle Lenses
We check contact lenses, intraocular lenses and spectacle lenses with regard to their parameters. We test with modern technology and according to current ISO standards and quality manuals.
Determination of essential contact lens parameters
Our device portfolio
Optical Coherence Tomography OCT is830
In order to measure the parameters of contact lenses, examiners sometimes need a large number of different devices to be able to measure them. These include the contact lens diameter, the base curve, the center thickness or thickness profile and the general profile. Due to the large number of necessary examinations and equipment, a great deal of time is required. Optical Coherence Tomography is particularly well suited to keep this time expenditure low and to make measurements consistently repeatable. Here, laser light (at a wavelength of 830nm) is sent through the scattering material (in special cases the contact lens) and compared with a reference. This comparison allows conclusions to be drawn about the different parameters of the scattering medium with the aid of special software solutions. The accuracy of the OCT is830 measurement method is in the micrometer range.
Using the modern OCT technology of the is830, we can determine the following contact lens parameters for you:
- Diameter of contact lenses
- Base curve of contact lenses
- Center thickness of contact lenses
- Thickness profile of contact lenses
- Edge profile of contact lenses
- Homogeneity of contact lenses
- comprehensive material library of all common contact lens materials
- Measurement of soft and rigid gas permeable contact lenses
- Measurements in immersion (saline) and in air
- Measurement of spherical and toric contact lenses
- Temperature-dependent measurements realizable by integrated temperature system
In addition, the OCT is830 offers comprehensive functions and software solutions for a wide range of contact lenses:
Evaluation of the Contact Lens Water Content - PCE MA50X
With the help of the precision moisture analyzer PCE MA50X we are able to make fast and accurate statements about the water content of soft contact lenses. The device is portable and can therefore also be used for external measurements. Through constant contact with the manufacturer and regular calibrations using standardized weights, we are able to provide reproducible and meaningful results.
The precision moisture analyzer PCE MA50X has the following specifications:
- readability 0.1 mg = 0.0001 g
- drying chamber with built-in infrared 450W radiator
- Definable abort criteria
- Definable measuring times
- Definable heating processes
Wettability of Contact Lenses - Topograph K5M
The wetting of the front surface of the contact lens plays a decisive role for the comfort of the wearer and the optics. Excellent wetting ensures a long-lasting pleasant wearing comfort. To determine the wetting of the contact lens under laboratory conditions, we use an experimental topographer (Oculus Wetzlar, Germany). Here, the contact lens is placed on a contact lens rest and illuminated with the help of a Placido ring system. With the help of simultaneous video recording, the change in reflection of the Placido rings allows us to detect when and where the wetting of the front surface of the contact lens changes.
With the help of the experimental topographer we can make the following measurements:
- Determination of contact lens wetting from special blister solutions
- Comparison of wetting of different contact lens materials
- Determination of the mode of action of different wetting agents
- Determination of different influences on wetting
- Creation of wetting profiles
Intraocular Lens & Contact Lens Power - Nimo Lambda X
Based on the patented “Phase Shifting Schlieren” (PSS) technique, we are able to measure the power and the power profile of all kind of contact lenses.
Get to know some special information about the Nimo Lambda X:
- Phase-Shifting Schlieren in transition mode
- measurement conditions dry or wet (e.g. saline)
- all types of soft and rigid gas permeable lenses
- spherical, toric and mutlifocal lenses
- high resolution modulation maps
Microscopy
For detailed images of contact lenses we use sophisticated technology from Jena. With the help of the stemi 305 microscope from ZEISS, we are able to visualize details that are not visible to the eye.
Get some information about what we offerwith Zeiss stemi 305 microscope:
- images up to a magnification of 40x
- frontlight and backlight situations
- comparitive images for different stress situations
- image integrated scale
Transmissibility - Spectrometer 100
Light transmission is a parameter that is given far too little attention when evaluating contact lenses. Not only the UV protection plays an important role here, but also the light transmission in the visible range.
With the help of a special test setup we are able to perform a variety of transmission measurements:
- measurements in the range 250 nm to 800 nm possible
- measurements in air and immersion (saline)
- comparison measurements before and after a stress situation
- informative transmission curves
- Verification of UV protection and UV block
Refractive Index - Refractometer VariRef C
The refractive index of a medium represents a ratio of the wavelength of light in a vacuum to the wavelength in the specific material. As a dimensionless number, the refractive index indicates how strongly the light is refracted by the specific medium (e.g. the contact lens)
With the help of the refractometer VariRef C extensive measurements are possible:
- measuring range 1.32000 to 1.58000 refractive index
- resolution 0.0001 refractive index
- precision and repeatability ± 0.0001 refractive index
- temperature chamber 5° Celsius to 80° Celsius
- temperature control by integrated temperature sensor (accuracy ± 0.03° Celsius)
Sterility
Testing for sterility serves the safety of the user and is therefore of great importance for both producer and user. Within a sterile environment (disinfected microbiological workbench) the product to be tested is removed with sterile disposable tweezers and placed on an agar plate with a nutrient solution. These are sealed and stored in an air-conditioned incubator for a defined period of time. Afterwards the germ growth can be tested.
With the help of our equipment we can carry out a large number of measurements:
- Determination of the germ load of a test product (e.g. for fungi)
- Storage of the test product for defined periods of time / temperatures
- Testing several products simultaneously
- Visual representation of the germ load
- Comparison measurements with a germ-contaminated product
