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Fill in the following chart using the information given. 

Patient 1: Rx: -7.50 -1.50 x180. Ks: 44.00/45.50. VD 10mm

                                            

On K                               Base curve: _____    Power of Tear Lens: _____     Power of Contact Lens -8.25 --> -7.50

0.50D Steeper than K     Base curve: _____    Power of Tear Lens: _____     Power of Contact Lens -8.75 --> -8.00

0.50D Flatter than K       Base curve: _____    Power of Tear Lens: _____     Power of Contact Lens -7.75 --> -7.00

Patient 2: Rx: -3.50 -0.75 x005. Ks 43.00/43.75. VD 10mm

On K                               Base curve: _____     Power of Tear Lens: _____     Power of Contact Lens -3.75

0.50D Steeper than K     Base curve: _____     Power of Tear Lens: _____     Power of Contact Lens -4.25 --> -4.00

0.50D Flatter than K       Base curve: _____     Power of Tear Lens: _____      Power of Contact Lens -3.25

Patient 3: Rx: +3.75 +0.50 x090. Ks 46.75/47.25. VD 8mm

On K                               Base curve: 46.75     Power of Tear Lens: 0            Power of Contact Lens +4.00

0.50D Steeper than K     Base curve: 47.25     Power of Tear Lens: +0.50     Power of Contact Lens +3.50

0.50D Flatter than K       Base curve: 46.25     Power of Tear Lens: -0.50      Power of Contact Lens +4.50 --> +4.75

Calculate the power  of the sphere RGP for the following patients: 

1. -4.00 +1.00 x090        42.00 / 43.00          CL BC: 42.50                          

2. +8.00 -2.00 x090        39.00 / 41.00          CL BC: 38.50                          

3. -3.00 -0.75 x180         41.00 / 41.75          CL BC: Fit on K                      

4. -3.50 +0.50 x090        42.50 / 43.00          CL fit 0.50D flatter than K       

5. -5.00 +1.00 x090        46.00 / 47.00          CL fit 0.75D steeper than K    

Describe how the following lenses fit on the patient's eye and what the power of the lacrimal lens is. 

1. K readings: 42.00 / 43.00   RGP BC: 43.00        Fit on K = 42.00

2. K readings: 43.00 / 42.00   RGP BC: 43.00        Fit on K = 42.00

3. K readings: 45.00 / 46.00   RGP BC: 44.00        Fit on K = 45.00  

4. K readings: 42.00 / 42.50   RGP BC: 42.00        Fit on K = 42.00

1. A patient has a -3.00D RGP with a BC of 7.50, which fits loosely. The technician chooses a lens with a BC of 7.45, and it fits perfectly. What power of RGP should be ordered?

2. A patient has a +2.00D RGP with a BC of 44.00, which fits too tight. The tecnician chooses a lens with a BC of 43.50, and it fits perfectly. What power should be ordered? 

3. If a patient has an Rx of -6.00 -2.00 x180 and K readings of 43.00 / 45.00, design an RGP's BC and Rx fit 1.00D steeper than K. 

4. If a patient has an Rx of -4.00 +1.00 x090 and K readings of 42.00 / 43.00, design an RGP's BC and Rx fit 0.75D flatter than K. 

5. If an RGP with a diameter of 8.5 is too losse, would you recommend an 8.0 or 9.0? 

6. if an RGP with a BC of 7.85 is too loose, would you recommed a 7.80 or 7.90? 

7. If an RGP has a diamter of 10.0 and is too tight, would you recommend a 9.5 or 10.5? 

8. If an RGP with a BC of 8.55 is too tight, would you recommend a 8.0 or 9.0? 

9. Which of the following is the flattest curve: 7.85mm/ 42.00D/ 7.50mm/ 41.00D? 

10. Which of the following is the steepest curve: 8.43mm/ 7.85mm/ 41.00D/ 42.00D? 

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