A patient's cycloplegic refraction shows +4.0 DS in the right eye while the manifest refraction shows +1.5 DS. The amount of latent hypermetropia is:

• A +2.5 DS (latent hypermetropia) ✓
• B +4.0 DS (total hypermetropia)
• C +1.5 DS (manifest hypermetropia)
• D +5.5 DS (absolute hypermetropia)

Explanation

Total hypermetropia = manifest + latent. Total = +4.0 D (cycloplegic refraction). Manifest = +1.5 D (unaided accommodation corrects this in young patients). Latent hypermetropia = Total − Manifest = 4.0 − 1.5 = +2.5 D (kept corrected by resting tonic accommodation of the ciliary muscle). Absolute hypermetropia is the part that cannot be corrected even with maximum accommodation. Latent hypermetropia is important when prescribing glasses, especially in children, as cycloplegia reveals the true refractive error.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.