1. Swing the Jackson cross-cylinder (JCC) in front of the patient’s eye to refine cylinder axis and power.
2. As a general rule, if the patient’s refractive error is primarily cylindrical, or if by retinoscopy or autorefraction you found 1.00D of cylinder or more, start by checking the cylinder axis first.

When performing refraction the Jackson cross cylinder is used to?

Cross cylinder examination (otherwise known as Jackson’s cross cylinder) is an examination used for the final fine-tuning of the axis and strength of astigmatism after its determination through retinoscopy, stellate cycle or automatic refractometry.

What is the principle of JCC?

The JCC is a Stokes lens composed of cylinders of low power (typically of +0.25 DC, or ±0.50 DC), with their axes crossed at 90°. It is designed to flip around an axis at 45° from the minus and plus axes, so that after one rotation of 180° the plus and minus axes are exchanged [2].

How do you do binocular cross cylinder test?

Place the cross cylinder lenses in front of the patient. Add plus lenses to the phoropter if the patient tells you that horizontal lines are darker and clearer when looking at the target. (Darker and clearer vertical lines imply a lead of accommodation.) The expected values for the FCC are +0.50D for every patient.

How do I get better at refraction?

Here are some general tips to get the best refraction for your patient:

1. Work with the smallest line that the patient can read.
2. “Which do you see better, #1 or #2?” Go all the way up to #10 (#3 or #4, #5 or #6, etc.)
3. If the patient pauses, show them the two options again, providing for two seconds on each option.

What is JCC lens?

A JCC is any lens power that is a spherical equivalent plano-powered lens. Examples include +0.25 sphere with -0.50 cylinder or +0.50 sphere power with -1.00 cylinder power, otherwise specified as ±0.25 or ±0.50. A patient uses a phoropter during an routine examination.

How well do we know the Jackson cross-cylinder?

Abstract The Jackson cross-cylinder is a lens of fundamental importance in optometry with a key role in the refraction routine. And yet it appears not to be as well understood as perhaps it should be.

When to check the cylinder axis for refractive error?

As a general rule, if the patient’s refractive error is primarily cylindrical, or if by retinoscopy or auto refraction you found 1.00D of cylinder or more, start by checking the cylinder axis first. Otherwise, start by checking the cylinder power first.

Why is retinoscopy and cross cylinder examination important?

With the advent of technology, techniques like retinoscopy and cross cylinder examination might seem outdated and useful only to the personnel of humanitarian missions. They do however provide an accurate alternative and their use gives a thorough understanding of the principles of refraction.