CL Introduction and Advantages

There are _____ types of contact lenses: soft contact lenses, rigid-gas permeable contact lenses, scleral contact lenses and hybrid contact lenses.

4

What are CLs Made From?

• Polymer

  • high-molecular weight chains

  • Both soft and RGP and scleral lenses

  • Poly = many

  • polymer - many strands plastic

• Soft Lenses

  • Water swollen into the lens as hydrophillic material

  • Hydro = water

  • Phillic = tendency toward

  • Hydrophillic = something that attracts/ has a tendency for water

  • Hydrogel material - three-dimensional networks composed of hydrophobic polymers synthesized by crosslinking water-soluble polymers

  • Silicon hydrogel material - a material used in contact lenses, combining the water-absorbing properties of hydrogels with the high oxygen permeability of silicone.

Soft, RGP and scleral lenses are made from ________.

Polymers

Aniseikonia

• Difference in cortical image size

• 2 different powered lenses (more than 3D)

Aniseikonia is the difference in ________ perceived between the eyes from unequal magnification.

Image Size

High Plus

• Ring scotoma - a type of visual field defect where there's a "blind spot" that appears as a ring in the visual field, with a central area of normal vision surrounded by a ring of impaired vision, and then normal peripheral vision.

• Class 2 drivers unsuitable in spectacles over +8D

• Vocational requirement

CLs are needed for lorry and bus drivers who have prescriptions ______+8D.

Over

What are the Requirements of a Contact Lens?

Check lecture recordings for this.