A Correct Statement regarding epithelial cells is that they: a)Comprise the posterior layer of the cornea b)Are unable to regenerate c)Comprise the thickest layer of the cornea d) Have the ability to reproduce - d) have the ability to reproduce Which of the following prescriptions indicates against-the-rule astigmatism? a)-4.50 +1.00 x75 b)-4.50 +1.00 x 180 c)-4.50 -1.00 x 165 d)4.50 -1.00 x 180 - a)-4.50 +1.00 x75 When a keratometer is being calibrated, which of the following targets ...

The tolerance for the overall lens diameter according to the ANSI standards is: A. +/-0.005mm B. +/-0.05mm C. +/-0.01mm D. +/-0.1mm - B. According to the ANSI standards (Z80.2-1989), the tolerance for the overall diameter of a contat lens is +/-0.05mm. ANSI standards have been developed to maintain quality in the contact lens industry. It is important to have an understanding of the ANSI guidelines. All of the following will enable the practitioner to verify the overall rigid gas ...

1. what medications may affect successful contact lens wear Antihistamines are beneficial when treating allergies and cold symptoms because they dry out the mucous membranes of the nasal passage. However, this may also lead to dehydration of the tear film. Antihistamines have also been known to slow down the blink rate and increase corneal sensitivity. 2. Sensitivity to light is known as _______. Photophobia refers to a sensitivity ("phobia") to light ("photo"). Presbyopia is the ...

Optic Zone - Central portion of a contact lens which contains the refractive power (generally corresponds to the corneal cap) Posterior Apecal Radius - Spin-cast soft lenses. (Curvature of posterior surface changes with refractive power. Measured at apex of posterior surface) Steeper Base Curve - As the Posterior radius of curvature is decreased the base curve becomes: (i.e. 8.4-8.1) Flatter Base Curve - As the Posterior radius of curvature is increased the base curve becomes: (i.e. 8...