Normal visual acuity of 6/6 is achieved by the age of:
**Core Concept**
Visual acuity is the sharpness and clarity of vision, and it is measured by the ability to recognize objects at a standard distance. Normal visual acuity of 6/6 is considered to be the standard for adults, which means that an individual can see objects clearly at a distance of 6 meters that a person with normal vision can also see at 6 meters.
**Why the Correct Answer is Right**
Visual acuity development in children is a gradual process that occurs over several years. The age at which normal visual acuity of 6/6 is achieved is around 7-8 years of age. This is because the retina and the visual pathway are still developing during childhood. The maturation of the retina, particularly the development of the macula and the fovea, is essential for achieving normal visual acuity. By around 7-8 years of age, the retina and the visual pathway have matured sufficiently for most children to achieve normal visual acuity of 6/6.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because visual acuity development is a gradual process that occurs over several years, and it is not a fixed age.
**Option B:** This option is incorrect because the age of achieving normal visual acuity of 6/6 is not around 5 years of age, as the retina and visual pathway are still developing during this period.
**Option C:** This option is incorrect because the age of achieving normal visual acuity of 6/6 is not around 10 years of age, as most children have already achieved normal visual acuity by this age.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that visual acuity development is a gradual process, and there is a wide range of normal. Some children may take longer to achieve normal visual acuity, and some may achieve it earlier. However, by around 7-8 years of age, most children have developed sufficient visual acuity to achieve a score of 6/6.
**Correct Answer: C. 10 years of age**