If one parent is nearsighted and the other is farsighted. One parent developed nearsightedness later in life, while the other was born farsighted and they are both the first ones in their family to have any sort of eye problems. Is there a possibility of their children having a perfect vision since both their conditions are the result of a recessive gene and can the probability of inheriting one over the other be assessed?
Both Nearsightedness and farsightedness are inheritable.
According to Citizen Scientists Look into Nearsightedness, 23andme blog:
Which types of eye disease are inherited?
Genetic factors play a role in many kinds of eye disease, including those diseases that are the leading cause of blindness among infants, children and adults.
More than 60 percent of cases of blindness among infants are caused by inherited eye diseases such as congenital (present at birth) cataracts, congenital glaucoma, retinal degeneration, optic atrophy and eye malformations. Up to 40% of patients with certain types of strabismus (ocular misalignment) have a family history of the disease and efforts are currently under way to identify the responsible genes.
In adults, glaucoma and age-related macular degeneration are two of the leading causes of blindness, and both appear to be inherited in a large portion of cases. Researchers have mapped several genes for glaucoma and are starting to identify genes involved in macular degeneration. They also are making very significant progress in identifying the genes that cause retinitis pigmentosa, a degenerative disease of the retina that causes night blindness and gradual vision loss.
Can common vision problems be inherited?
Genetics also play a role in vision problems that occur in otherwise healthy eyes. Genetic ophthalmologic researchers now have evidence that the most common vision problems among children and adults are genetically determined. The list includes strabismus (cross-eyes), amblyopia (lazy eye) and refraction errors such as myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
Can inherited eye diseases be corrected if an early diagnosis is made?
This Table gives a better insight on Causes of Myopia: