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: 44.00 Power of Tear Lens: 0 Power of Contact Lens -8.25 --> -7.50
0.50D Steeper than K Base curve: 44.50 Power of Tear Lens: +0.50 Power of Contact Lens -8.75 --> -8.00
0.50D Flatter than K Base curve: 43.50 Power of Tear Lens: -0.50 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: 43.00 Power of Tear Lens: 0 Power of Contact Lens -3.75
0.50D Steeper than K Base curve: 43.50 Power of Tear Lens: +0.50 Power of Contact Lens -4.25 --> -4.00
0.50D Flatter than K Base curve: 42.50 Power of Tear Lens: -0.50 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 = -3.50 + (-0.50) = -4.00
2. +8.00 -2.00 x090 39.00 / 41.00 CL BC: 38.50 = +7.00 + (+0.50) = +7.50 --> +8.25
3. -3.00 -0.75 x180 41.00 / 41.75 CL BC: Fit on K = -3.25 + (0) = -3.25
4. -3.50 +0.50 x090 42.50 / 43.00 CL fit 0.50D flatter than K = -3.25 + (+0.50) = -2.75
5. -5.00 +1.00 x090 46.00 / 47.00 CL fit 0.75D steeper than K = -4.50 + (-0.75) = -5.25 --> -5.00
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. The CL is steeper by 1.00D, so the LL is +1.00.
2. K readings: 43.00 / 42.00 RGP BC: 43.00 Fit on K = 42.00. The CL is steeper by 1.00D, so the LL is +1.00.
3. K readings: 45.00 / 46.00 RGP BC: 44.00 Fit on K = 45.00. The CL is flatter by 1.00D, so the LL is -1.00.
4. K readings: 42.00 / 42.50 RGP BC: 42.00 Fit on K = 42.00. The CL BC equals flaty K, so the LL is 0 or plano.
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? 7.50 (45.00D) --> 7.45 (45.25D) is 0.25D steeper. -3.00 + (-0.25) = -3.25
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? 44.00 --> 43.50 is 0.50D flatter. +2.00 + (+0.50) = +2.50
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. = 44.00D/ -7.25
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. = 41.25/ -2.75
5. If an RGP with a diameter of 8.5 is too losse, would you recommend an 8.0 or 9.0? 9.0
6. if an RGP with a BC of 7.85 is too loose, would you recommed a 7.80 or 7.90? 7.80
7. If an RGP has a diamter of 10.0 and is too tight, would you recommend a 9.5 or 10.5? 9.5
8. If an RGP with a BC of 8.55 is too tight, would you recommend a 8.0 or 9.0? 9.0
9. Which of the following is the flattest curve: 7.85mm/ 42.00D/ 7.50mm/ 41.00D? 41.00D
10. Which of the following is the steepest curve: 8.43mm/ 7.85mm/ 41.00D/ 42.00D? 7.85mm