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1 Rebecca Johnson, CPOT, COT, COE My glasses fog and I have to clean them too often. Frame Adjust tilt or increase vertex distance. If the frame is rubbing against the cheeks or eyebrows, consider a smaller frame. Job/hobbies If the lenses are glass, change to plastic as plastic conducts heat more poorly than glass. Medical condition Epiphoria (over-tearing) could cause the glasses to fog. Seborrhea dermatitis (dandruff) could cause dirty lenses. Proper lens choice Give the patient a bottle of lens cleaner for ant-reflective lenses and explain that anti-reflective lenses tend to show smudges easier due to the coating. Newer lens technology has improved upon this problem, but some less expensive lenses still cause problems in this area. Opticote Anti-fog lens coating. vision. I love the look of my high index lenses, but I am not happy with my Chromatic aberrations Chromatic aberrations are more noticeable in high index lenses. Chromatic aberrations happen when a white light is viewed away from the optical centers and are more noticeable in high index lenses. Suggest AR coat. Page 1

2 Check refraction How much did the cylinder change? Was there a change in axis? I could see fine when I first got my new glasses, but now my vision is blurry. A patient with this complaint needs to be re-examined with dilation. Diabetes Uncontrolled glucose levels can affect the crystalline lens, causing a fluctuation in refractive error. Discuss blood sugar levels with the patient. What was the blood sugar on the day of the exam? Is it under control? Some patients never know they are diabetic until their vision starts fluctuating. Cataract Cataracts cause a change in the refractive index of the crystalline lens, usually requiring more minus power. Old timers used to call this getting second sight as they found that as the cataract advanced, the near vision became clearer due to the induced myopia. Macular edema Swelling of the macula can cause the vision to be more hyperopic due to the change in the axial length of the eye. I don t see well when driving at night. Cataract/glare Certain types of cataracts will cause difficulty with night driving glare. Irregular or uncorrected astigmatism The patient might have some irregular astigmatism, which would become more pronounced when the pupils are dilated, as they would be in the dark. Accommodation When it is dark and there is no accommodative targets, a young patient might fog himself due to over-active accommodation. Page 2

3 My eyes feel like they are pulling with my new glasses. Induced prism If the optical centers are not correct, there will be an induced prismatic effect. This is more crucial with higher power lenses. I see double with my new glasses. Overlooked prism Is the patient supposed to have prism in the glasses? (Check old pair) Sometimes the prism is overlooked. Anisometropia Is there a large refractive error between the 2 eyes? A common example of this is post cataract surgery when only one eye has been operated on and is now plano, but the other eye is still very myopic or hyperopic. Usually surgery is done within a week to prevent this problem. Medical condition Do they also see double without the glasses? Don t forget to rule out a medical problem, such as third nerve palsy (diabetes). Something just is not right. Axis change Has the axis changed more than 10 degrees? Patients with higher cylinder powers will notice axis changes much more. Base curve Check the base curve of the previous and the new glasses with a Geneva lens clock. If the base curves are off more than one diopter of the old base curve, the patient will notice that something is different, but may not Page 3

4 be able to give a good description of the problem. The base curve measurements become more important with higher powers. Significant change in frame size or style Newer fashion frames are smaller, thus not allowing for as large a view as the patient has been used to. The patient can probably get used to this if they are happy with the look of the frame. I can t read with these glasses. Seg height Traditional bifocal-look at the old glasses seg height. Even if this is clinical wrong, this may be the height the patient has become accustomed to. PAL mark up the lenses to be certain that the centers are correct. First time progressives First time progressive-if the centers are correct, train the patient how to use the lens. The add may need to be bumped a little if the patient is not using the maximum power. Size and style of frame Small, stylish frames can be so small that part of the progressive add is cut off. Reading distance Reading distance-discuss the distance the patient uses the most for near work. Total reading prescription power Remember to keep in mind the total prescription power. If I put my glasses here, I can see better. Power change Moving the glasses down on the nose creates a power change. The patient needs to be refracted. Page 4

5 Vertex distance If the lens is high power (+/- 5 D) vertex distance becomes a factor. The patient may have been refracted at a vertex distance that is different from the eyeglass frame. Check the vertex distance on the frame and compare it with the refraction VD.hint the normal refraction VD is 14 mm. WAAAAA! Complainer? Some people just like to complain. May not like frames This poor guy went home with these frames.his girlfriend had a fit. She told him to do whatever it took to get a different frame. This lady was so happy to get larger frames..like her sister has. But, when she went home and looked in the mirror, she wished she had listened to the advice of the optician and went with the smaller frames. Page 5