Background: Achromatopsia is a congenital, autosomal recessively inherited condition in which cones are either defective or absent. Complete achromatopsia results from having only rods as functioning photoreceptors. Many people with achromatopsia have small amounts of residual cone function that may provide minimal color vision under special circumstances. Clinical findings associated with the condition include reduced visual acuity, nystagmus, a greater than normal incidence of high ametropia, and severe photophobia. The photophobia resulting from achromatopsia can be debilitating even in normal indoor illumination. Tinted contact lenses have been reported to reduce photophobia and improve visual function in these patients.
Cases: Two cases are reported here. A 32-year-old man presented with reduced and stable visual acuity, complete color blindness, nystagmus, and debilitating photophobia. The second patient was a 23-year-old woman who presented with reduced and stable visual acuity, severely impaired color vision, rotary nystagmus, and significant photophobia. Both of these patients were fit with centrally tinted contact lenses. Although visual acuity did not improve measurably in either patient with tinted compared with clear lenses, both experienced a dramatic reduction in photophobia with the lenses.
Conclusion: Tinted spectacle or contact lenses may be useful in relieving photophobia associated with a number of cone disorders, including achromatopsia. In addition to decreasing light sensitivity, tinted lenses have been reported to improve visual acuity, decrease the size of central scotomata, enlarge peripheral visual field, and enhance visibility of long wavelength stimuli in bright illumination.