Nuclear cataract

This is an accentuation of a normal condensation process in the lens nucleus. It usually becomes evident at about 50 years of age, and progresses slowly until the entire nucleus is opaque. The nucleus changes from yellow to brown - the nuclear brunescent cataract.

• there is gradual reduction in contrast and colour intensity
• patients have difficulty in recognizing faces or car number plates
• retains good reading vision for level of Snellen acuity

An early indication is a change in the refractive index of the lens. This may be an increase in myopia, or a decrease in hypermetropia. The improved near vision may cause the patient to believe erroneously, that their sight has improved. However, as the opacity progresses, both far and near vision deteriorate.

Reference:

1. Allen D. Cataract and surgery for cataract. BMJ. 2006 Jul 15;333(7559):128-32.