Optometry Flashcards

Which term describes the condition where the eye's refractive power is too strong relative to its axial length, causing light to focus in front of the retina?

Answer: Myopia

Myopia (nearsightedness) occurs when the refractive power is excessive or the eye is too long, focusing light anterior to the retina.

A patient has a prescription of -3.00 +1.50 x 090. What is the spherical equivalent?

Answer: -2.25 D

Spherical equivalent = sphere + (cylinder/2) = -3.00 + (1.50/2) = -3.00 + 0.75 = -2.25 D.

Which type of astigmatism has both principal meridians myopic?

Answer: Compound myopic astigmatism

Compound myopic astigmatism occurs when both focal lines fall anterior to the retina, making both meridians myopic.

The near point of accommodation in a patient suddenly receding could indicate which condition?

Answer: Early presbyopia

A receding near point of accommodation is a hallmark sign of presbyopia, typically beginning around age 40.

When performing retinoscopy, the examiner observes a 'with' movement. This indicates the patient's refractive error is:

Answer: More hyperopic than the working distance lens

A 'with' reflex during retinoscopy indicates the patient's far point is behind the examiner, meaning more hyperopia exists than the working distance compensates for.

Which instrument measures corneal curvature and is used to fit contact lenses?

Answer: Keratometer

The keratometer measures the radius of curvature of the anterior corneal surface, expressed in diopters or millimeters.

A keratometry reading of 44.00 D @ 180 / 46.00 D @ 090 indicates:

Answer: With-the-rule astigmatism

With-the-rule astigmatism is present when the steeper meridian is vertical (near 090), requiring a minus cylinder axis at 180.