In addition to improving vision, are you aware of the array of benefits that premium lenses can offer your patients? Over the past several years, research has shown how premium lenses can help certain patients.
UV light can contribute to the development of cataracts, pingueculae, pterygia and skin cancers of the eyelid.1 Also, long-term chronic exposure to short-wavelength visible light and near UV radiation may lead to age-related macular degeneration (AMD).2
Glasses with yellow filters that reduce short wavelengths and remove wavelengths below 400nm should regularly be worn.2 People who spend much time outdoors should regularly wear glasses that reduce the blue end of the solar spectrum (i.e., 400nm to 500nm).2
San Diego optometrist Brian Chou prescribes lenses that offer UV protection for patients with cataracts because UV light can further cataract progression, especially in cortical cataracts.3
Maximal UV light protection is a good idea for patients with conditions such as herpes simplex keratitis and toxoplasmosis, because UV light might trigger recurrence of the infection, Dr. Chou adds.
Also consider prescribing UV-filtering lenses for patients who take antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), psychotherapeutic agents and some herbal medicines because these agents may cause ocular phototoxicity.4
Tinted lenses offer patients several advantages that you might not have considered. These include:
Improved reading comfort and performance. Tinted lenses may filter out certain light frequencies and reduce the amount of information the eyes absorb. Some researchers believe that by reducing the amount of information, the brain can better process what the eyes see.
In one study, blue filters led to significant improvement in the number of fixations and regressions and the rate of reading in children with reading disabilities.5 Another study of children and adults with learning disabilities showed that the rate of reading was significantly faster in subjects who read with glasses that had a colored overlay compared with those who read with glasses without a colored overlay.6
|Improved reading performance in children is one of the many benefits of premium lenses.|
In a different study, researchers followed 68 children who wore lenses with colored overlays that provided appropriate chromaticity under conventional white fluorescent light for one month. In the second month, the children wore lenses of a similar color but with a chromaticity outside the range in which perception is reported to improve. The children recorded symptoms of eyestrain and headache in a diary; these were less frequent on days in which they wore lenses with colored overlays.7
Tinted lenses can help patients with reading disabilities, but does the color of the lens matter? Research by optometrist Harold A. Solan from New York, has demonstrated that blue light filters are superior to other color filters.5,8 In one study, comprehension scores of children with reading disabilities improved significantly when they read with blue filters and borderline significantly with dark gray filters, but not with light gray filters or no filters.8
Another study by Dr. Solan found that blue filters caused a significant improvement in the number of fixations and regressions and rate of reading in children with learning disabilities.5 Therefore, blue filters appear to be the most effective at improving reading disabilities.
Reduced migraines. Patients who experience migraines may be hypersensitive to visual stimuli. Colored filters can reduce symptoms caused by these stimuli.
In one study, patients who experienced migraines were more susceptible to pattern glare than those who did not experience migraines. Tinted lenses reduced pattern glare, which may have reduced migraines.9
Lens color may also affect whether tinted lenses reduce migraines. In one study, children who wore lenses with either a rose or a blue tint experienced migraines less frequently after one month. At four months, however, only children wearing rose-tinted lenses continued to experience migraines less frequently. This improvement in migraine frequency is related to a reduction in visually-provoked beta activity.10
Reduced epilepsy symptoms. In one study, researchers prescribed tinted lenses for patients who were diagnosed with photosensitive epilepsy. All patients suffered from visually provoked seizures. Initially, 70% of patients said they experienced beneficial effects from tinted lenses. More than two years later, 57% of patients reported benefits and said they were still using the tinted lenses. About half these patients reported pronounced benefits, such as reduced dizziness from fluorescent lighting and eliminated aura when looking at computer screens. However, only three patients experienced a reduction of seizures due to tinted lenses.11
Patients with certain conditions or lifestyles may benefit from premium lenses. I often prescribe special lenses for computer use and add tints when people need to work under uncomfortable lighting, says optometrist Gary J. Williams, of Owego, N.Y. These lenses enhance visual function and comfort, he says.
Optometrist Peter G. Shaw-McMinn, assistant professor at Southern California College of Optometry, recommends premium lenses for patients with cataracts, AMD and corneal dystrophy. Because they require the best possible image on their retina, they may benefit from features that can help them see better, such as anti-reflective coating, which permits more light through the lens to the eye and decreases ghost images, he says.
Dr. Shaw-McMinn also stated that UV 400 can protect their eyes from the sun and inside light, and decrease the scattering of light. I might also recommend tints (rose, pink) to block the short wavelengths of visible light to decrease scattering, says Dr. Shaw-McMinn. Patients with AMD are especially affected by glare sources. A bright flash will temporarily blind them while their photoreceptors are regenerating chemicals. AR and polarized lenses reduce the chance for this disabling glare.
When prescribing lenses for your patients, consider their health conditions and lifestyles. They may benefit from premium lenses.
1. Castellano CF. Getting it together: plano sunwear and CLs go hand in hand. 20/20 2005 Jan 1;32(1):26.
2. Waxler M, Hitchins VM, eds. Optical Radiation and Visual Health. Boca Raton, Fla.: Crc Press, 1986:62-3.
3. Taylor HR, West SK, Rosenthal FS, et al. Effect of ultraviolet radiation on cataract formation. N Engl J Med 1988 Dec 1;319(22):1429-33.
4. Glickman RD. Phototoxicity to the retina: mechanisms of damage. Int J Toxicol 2002 Nov-Dec;21(6):473-90.
5. Solan HA, Ficarra A, Brannan JR, Rucker F. Eye movement efficiency in normal and reading disabled elementary school children: effects of varying luminance and wavelength. J Am Optom Assoc 1998 Jul;69(7):455-64.
6. Bouldoukian J, Wilkins AJ, Evans BJ. Randomised controlled trial of the effect of coloured overlays on the rate of reading of people with specific learning difficulties. Ophthalmic Physiol Opt 2002 Jan;22(1):55-60.
7. Wilkins AJ, Evans BJ, Brown JA, et al. Double-masked placebo-controlled trial of precision spectral filters in children who use coloured overlays. Ophthalmic Physiol Opt 1994 Oct;14(4):365-70.
8. Solan HA. The effects of varying luminance and wavelength on reading ability in good and poor readers: is there a transient system deficit? American Optometric Association meeting, New Orleans; January 1996.
9. Evans BJ, Patel R, Wilkins AJ. Optometric function in visually sensitive migraine before and after treatment with tinted spectacles. Ophthalmic Physiol Opt 2002 Mar;22(2):130-42.
10. Good PA, Taylor RH, Mortimer MJ. The use of tinted glasses in childhood migraine. Headache 1991 Sep;31(8):533-6.
11. Wilkins AJ, Baker A, Amin D, et al. Treatment of photosensitive epilepsy using coloured glasses. Seizure 1999 Dec;8(8):444-9.