Test configuration
Contact Lens
Contact lenses are thin lenses placed directly on the surface of the eye to correct visual defects.
About this material
Contact lenses are thin lenses placed directly on the surface of the eye to correct visual defects.
Mechanical testing applications
Mechanical testing of contact lenses is key to understanding their clinical quality and performance. Measured properties consist of on-eye movement, fitting, wettability, elasticity and durability. Moreover, contact lenses are subjected to various wear modes such as daily disposable, frequent replacement and extended wear. Common mechanical tests of contact lenses are tensile and tear testing which are performed in a saline bath to mimic the eye's physiological environment. More recently, tribology assessment such as frictional tests are performed to determine lubricity of contact lenses. Mechanical testing of contact lenses will aid in the development of this product.
Test configurations (13)
Test configuration
Tension
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Unconfined Compression
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Indentation (Stiffness)
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Friction
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3D Thickness Mapping
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Temperature Control
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Puncture
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External Analog Sensors
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Camera Feed
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Positioning (Manual)
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Positioning (X Auto)
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Positioning (XY Auto)
Case studies (1)
Related resources (1)
FAQ
How does the "Sinusoid" model works?
This feature is used to obtain the Frequency, Amplitude and Offset of a sinusoidal signal. A blue line displays the theoretical sinusoid with the Frequency, Amplitude and Offset obtained (Figure 1). The values of the Frequency, Amplitude and Offset are indicated in the "Results" field. The units vary according to the graph’s axes.
This feature can also be used for sinusoidal stimulus-response analysis. Sinusoidal stimulus shall be selected on the x-axis and the sinusoidal response on the y-axis. The Modulus is the ratio of the response Amplitude over the stimulus Amplitude. The Phase is the phase difference between the response and the stimulus. The Modulus’ is computed as the Modulus*Cos(Phase) and the Modulus” is computed as the Modulus*Sin(Phase). A blue line displays the theoretical sinusoidal stimulus-response with the Frequency, Modulus and Phase obtained (Figure 2). The values of the Modulus and Phase are indicated in the “Results” field. The units vary according to the graph’s axes.
One use for this feature would be to compute material properties by multiplying the Modulus obtained by the appropriate geometric factors. For example, the Young’s Modulus can be obtained during uniaxial compression or tension on cylindrical sample with t/pi*r2 as the geometric factor, t is the thickness and r is the radius of the sample.
Mach-1 Analysis – Sinusoid – Example for stimulus-response analysis
What is the ultimate tensile strength (tensile strength)?
Ultimate tensile strength is the maximum stress developed in a material before rupture in a tension test.
What is the elasticity?
Property of a material to deform under load or strain and to return to its original shape when the stress is released.
LAB MODULE – Unconfined Compression of Hydrogel Disks – Student Version